Friday, February 3, 2012

Rattlesnake Slope, Frenchman Coulee, Lower Grand Coulee and Palouse Falls

Recent photos of features created by outburst floods from Glacial Lake Missoula near the end of the most recent Ice Age. Photos here are from several winter 2011-2012 hikes with 9-year-old nephew Luke, along with miscellaneous shots from the Palouse Falls area - plus a few extras.


Click images to expand.


Rattlesnake Mountain ice age flood erratic.
One of the oldest rocks in the Pasco Basin.

Luke examines geocache contents while sitting on ice-rafted erratic boulder (Rattlesnake Mountain in distance).

The argillite boulders (pictured above) consist of material that was part of an ancient seabed more than a billion years ago and later involved in the uplift of the Rocky Mountains.

During the last Ice Age, the rocks became trapped within glacial ice in British Columbia or northern Idaho. That ice was picked up and carried into the Pasco Basin by an Ice Age Flood from Glacial Lake Missoula. Note: B.C. material would have been moved south within glacial ice - Into the path of Lake Missoula floodwaters.

More on this feature below

Columbia River Basalt Group column near Frenchman Coulee.
Luke and interesting basalt column near Echo Basin rim (Frenchman Coulee). And yes - seconds after I took this photo he was trying to climb it.

Columbia Plateau or Basin petroglyphs.
Wisdom and Grand Coulee petroglyphs.

Luke and I visited several geocaches on our recent hikes. We found this guy in a cache called "The Snake Den" near Agatha Tower. The little owl named "Wisdom" has an ID tag with a tracking number.


A fourth grade class in Newman Lake, Washington is tracking Wisdom's travels as they study Washington State. He was sent out on an adventure to visit cities in Washington. I guess the basalt views are a bonus for the little guy.


Luke took him back to the Tri Cities via Ellensburg before placing him in a cache near Lake Lenore. Wisdom saw some interesting Ice Age Floods features along the way. He also had a chance to visit these amazing petroglyphs.


Teresa Foster and Palouse Falls.
Here's a shot of Teresa on a windy morning at Palouse Falls State Park. Not much ice left at the end of January compared to trips earlier this winter - see below.

Palouse Falls in winter.
I posted this one on the HUGEfloods site. Sure was a nice afternoon. Had the canyon to myself ... Set timer on camera and ran to the pool.

The Tri City Herald used this shot on their front page in mid-December. I heard from quite a few people that wanted directions to the park. Great views from the overlook. There is not a maintained trail to the lower pool. The Herald ran two additonal Palouse Falls photos on Page 1 earlier in the year - one showing January ice and another when flows exceeded 5,000 cubic feet per second in April. I'll post them below.

Palouse Falls ice.
Cold mist and slippery rocks near the falls.

Palouse River Canyon.
Nice down here except for a huge amount of litter.

Palouse River Canyon, Ice Age Floods Institute.
I made several visits to the park this winter to sack up and haul trash out of the canyon. Thanks to Rick and Cliff for helping on one of the trips. I've got some friends from the Ice Age Floods Institute lined up to help next year.

Palouse River.
Cha-ching!!!

Found two full ones.

Hauling trash out of the Palouse River Canyon.

That's Cliff Burt near the top. Not that hard to get out of here but ... as you try to maneuver sacks through brush and a slot in the canyon wall - You sure think bad thoughts about the slobs that leave trash on the canyon floor.


On the climb out your clothes soak up most of the old beer leaking from the sacks.


Palouse Falls.
Palouse Falls shots with lots of ice were taken mid-December.

Scott Burns Cataclysms on the Columbia: The Great Missoula Floods.
A quick stop at the falls (29 Jan 12) - on our way to hear geologist/author Scott Burns talk about his book Cataclysms on the Columbia: The Great Missoula Floods at Spokane Community College.
On this day the Palouse River carried some soil. Pool below falls looked like chocolate milk.

Dr. Scott Burns Ice Age Floods. Cataclysms on the Columbia: The Great Missoula Floods.
Thanks to the Spokane Community College Science Department for hosting Dr. Burns as part of their Geology Lecture Series. The place was packed ... They were able to quickly set up a video feed to a large classroom across the hall for those that didn't get seated in the auditorium.

Proceeds from his book sales help fund scholarships in the Geology and English Departments at Portland State University.

Palouse River flow over Palouse Falls - Teresa Foster.
Teresa loves Palouse Falls - she attended sixth grade in nearby Kahlotus. The flow on this day was about 575 cubic feet per second. Two days later - warmer temps led to melting snow upstream and a 2,500 cubic feet per second flow.

Real-Time Palouse River Flow

I wish more people would visit that park. My favorite times are spring and early winter. My best advice for finding a bunch of ice is to watch for long periods of cold weather with NO warm days mixed in. The ice is usually slow to build and is quickly shed from canyon walls when temperatures warm. A Discover Pass is required to enter the park.

Palouse River Canyon.

Frosty canyon view - January 2011

This image and the one below are the other two used by the Herald last year. Click to expand this shot. Try to imagaine canyon completely filled with Ice Age Floodwater. Once again ... I had the place to myself.

Palouse Falls State Park.
April 2011 flow.

Palouse Falls is impressive at 5,000+ cubic feet per second - but that's just a tiny trickle compared to the Ice Age flows! On big flow days you'll probably find a few others at the viewpoint.

Washtucna Coulee.
Frosty Washtucna Coulee

This ditch was way too small to handle Cheney-Palouse volumes as Glacial Lake Missoula drained! Like Palouse River Canyon and Devil's Canyon - HU Ranch Coulee was created when floodwaters overtopped the south rim of Washtucna Coulee and found huge fractures in the basalt. The floods cut deep channels in these locations between Washtucna Coulee and the Snake River.


HU Ranch Coulee.
On the way to Palouse Falls - Crossing upper HU Ranch Coulee.


HU Ranch Coulee Ice Age Floods channel.
SR-261 climbs out of HU Ranch Coulee near entrance to Palouse Falls State Park.

Geocache Trackable.
Here's another geocache "Trackable" Luke ended up with. This guy (Salt and Pepper) was found on a highpoint near Island Plateau in Grant County.

Ice Age Floods erratic in Pasco Basin.
Tom and Luke on argillite erratic.

New Year's Eve hike to Bruce Bjornstad's Rattlesnake Slope Erratics geocache. Argillite boulders above Columbia River Basalt - pretty cool story.

Lake Missoula flood erratic.
Luke hides cache container (with Salt and Pepper inside) among argillite boulders.

Frenchman Coulee aerial map.
Red line shows part of the route Luke and I took around Echo Basin. Frenchman Coulee is a great place to visit if you're interested in the Ice Age Floods. A Discover Pass is required to park in this area.

Ellensburg Ice Age Floods Institute field trip.
Field trip lecture (top right)

Looking down rib that separates Frenchman Coulee and Echo Basin. This shot was taken during the Ellensburg Chapter of the Ice Age Floods Institute fall field trip. That adventure was lead by chapter President Nick Zentner (CWU geologist).

Nick Zentner Central Washington University.

Nick uses a small tub to illustrate Quincy Basin overflow. Water bottle discharge represents Ice Age Floodwater pouring from Grand Coulee into the Quincy Basin. The two small streams flowing from Nick's tub are Potholes Coulee and Frenchman Coulee. (When Nick gets really good at this he'll be able to also show flow through Drumheller Channels, Crater Coulee, Gorge Amphitheater and a small dribble between Potholes and Crater Coulees.) The point of this talk was the formation of Frenchman Coulee - Great job Nick!

I understand that Nick had 167 in attendance at the February 2012 Ellensburg IAFI meeting.

Grand Coulee, Soap Lake and Quincy Basin view.
I hope I don't get you turned around here. The view in this shot is looking south into the Quincy Basin (Note location of Soap Lake). This is the mouth of the Grand Coulee. Huge volumes of floodwater shot out of this channel into the Quincy Basin. Large sediment (boulders) dropped out of the flow as the Grand Coulee floodwaters spread out into the basin.

Soap Lake, WA.
While we're in this area ... Here's a better shot of Soap Lake. On windy days white foam accumulates on the shore.

Ephrata Fan south of Soap Lake, WA.

A strange place - The Ephrata Fan. This shot looks north to the Grand Coulee.

South of Soap Lake (and southwest to Ephrata) are several miles of boulder-covered terrain (more boulders under the boulders you can see). The velocity of the flow in the Grand Coulee was strong enough to tumble this material in the bedload. As soon as the water had room to spread out - the depth and speed of the current was reducued and these things settled to the bottom of the temporary body of water that filled the Quincy Basin.


Don't miss this feature if you're new to the Ice Age Floods story. A couple friends that I've taken around to various features have told me that they didn't really "get it" until I showed them the Ephrata Fan at the mouth of the Lower Grand Coulee.


You can view a similar boulder field south of Sentinel Gap between the highway (SR-243) and Columbia River.

Sentinel Gap trip report.


Teresa Foster and Ice Age Floods erratic boulder below Sentinel Gap.

Teresa inspects a large erratic boulder south of Sentinel Gap. Note the surrounding basalt boulders. Just like the Ephrata Fan (picured above) boulders dropped out where the floodwaters spread out entering the Pasco Basin.

Lake Missoula flood debris below Sentinel Gap. Near Mattawa, WA.
Flood debris below Sentinel Gap makes it tough to develop expansive lawns.

Lake Bonneville flood boulders near Swan Falls. Snake River Canyon.Drive south of Boise, Idaho to see yet another impressive boulder field downstream from a constriction. Boulders shown in this image are sitting below Swan Falls along the Snake River. These boulders were tumbled and piled by the Bonneville Flood.



Creative fence building on the Ephrata fan.



As you travel south on the Ephrata Fan - you'll notice the floods have graded the material. The boulders get smaller and smaller. The farther south you go the smaller the stones. Some farmers have removed rocks from fields to allow farming. Another mile or two south and you'll start seeing healthy crops in good soil under pivot irrigation systems.

Brent Cunderla BLM - Ice Age Floods Sandhill Crane Festival Field Trip.
Many huge boulders moving with the Grand Coulee floodwaters did not settle out near Soap Lake - They were rafted south within icebergs. Some icebergs grounded and later melted - leaving clusters of erratics. This group of boulders were stranded on the northern slopes of the Frenchman Hills (south rim of Quincy Basin). When the Grand Coulee Project was built and irrigated farms were developed - Many erratics were blasted and moved to the edge of the fields or used as fill.
Photo shows: Brent Cunderla (blue/black coat at center) - BLM geologist and President of the Wenatchee Chapter of the Ice Age Floods Institute leading Ice Age Floods field trip during the Othello Sandhill Crane Festival.

Glacial debris - Source of Ice Age Flood erratics.
Photo shows glacial debris on Mt. Rainier. Glaciers are often known as "Nature's conveyor belts". Vist Mt. Rainier in late fall to see boulders that have accumulated on and within glacial ice.

Columbia Basin Agriculture - Ice Age Floods.
Huge out of place boulder near George, WA (Quincy Basin). Some of the lone boulders separated from icebergs and plunged to the bottom of the temporary body of water that filled the Quincy Basin. Isolated erratics distributed in this manner are known as Drop Stones. Either road builders or farmer have shoved this one around.

Ice Age erratic Frenchman Coulee.
Notice the angular shape of this Frenchman Coulee Rib erratic. The lack of rounding tells us that this is pretty much where the iceberg left it (no bedload tumbling).
I carry this hammer for scale only (9' handle). I've never struck a rock with it.
Please leave erratics as you find them. Thanks!

Echo Basin are Frenchman Coulee Ice Age Floods aerial.
Red line - Tom and Luke route.

Sorry I got off track with the boulder deposits. Point was ... floodwaters filled Quincy Basin ... big stuff settled out early and the escaping water cut into the basalt carving scabland channels and magnificent coulees like Echo Basin pictured here. Hiking around rim you get some great views of columnar basalt and a gigantic plunge pool.

Columbia River near Vantage, WA.
Columbia River flows south through Sentinel Gap in the distance. Note I-90 and Vantage Bridge (Vantage, WA far shore).

Frechman Coulee geocache.
Luke reaches into "The Snake Den" geocache. In warmer months I'd suggest using caution when reaching under this and similar rocks in the area. Seems to be a healthy rattlesnake population near Frenchman Coulee and Babcock Bench.

Sunshine Wall in Echo Basin.
Here's that owl again - This time in front of Sunshine Wall (north wall of Echo Basin). Luke found him in the container pulled from "Snake Den" geocache.

Follow the owl's adventure at:
Wisdom's Page


Columbia River basalt flows.

"GC" on highpoint above Island Plateau is where the little panda bear pictured above was found. The floods sure did an amazing job taking the basalt flows apart in this area.

Columnar Basalt, Ice Age Floods.
Luke hops around on Roza flow column tops near Bruce Bjornstad's Frenchman Coulee Rib geocache.

Drumheller Channels Columbia River Basalt.
Photo taken spring 2011 shows columnar basalt tops in Drumheller Channels.

Ice Age Floods, Drumheller Channels.
Here's another shot from the top of a Drumheller Channels mesa/butte. This columnar basalt exposure looks like a cobblestone path.

Frenchman Coulee, Potholes Coulee columnar basalt.
Exposed basalt column tops between Frenchman and Potholes coulees.

Mount St. Helens ash layer in Columbia Basin.
Luke was interested in the 1980 Mount St. Helens ash layer.


Columbia Basin geocache.
Eyes glued to GPS


Sand dunes near Columbia River.
Lunch break on a large dune.


Lake Missoula Floods.
Photo taken from the west side of Columbia River (Fall 2011 hike). You can see our track over the dune at lower right.Lake Missoula floods easily removed basalt columns. Another view of point marked "GC" above Island Plateau.

Vantage area sand dunes.
I think this is where we got the sand in our shoes.


Columbia River sand dunes.
Stopped to empty shoes before short hike up to Island Plateau.

Climbing basalt.
En route to Island Plateau

Luke stands on solid Columbia River Basalt Group footholds while his spotter steps away to snap a quick photo.

Basalt column.
I sure like that column.


Columbia Basin geocache near Ice Age Floods erratics.
Luke opens geocache at the point marked "GC" in previous photos.

A couple huge ice-rafted erratics (shown in the next two photos) sit on hillside beyond "Columbia River" notation.

Ice Age Flood erratic carried to this point on Glacial Lake Missoula Floods.
Here's one of them.


Another Ice-rafted erratic boulder left by Ice Age Floods from Glacial Lake Missoula.
View from this erratic includes Columbia River - arrow points to the highpoint you know as "GC".

Kittitas County deer and elk.
Lots of deer and elk on Kittitas County side. Frenchman Coulee behind antlers. I now leave these things where I find them. When you start hiking in the scabland you end up with a pile of them.

Frenchma Coulee and Echo Basin.
One more Frenchman Coulee view from the other side of Columbia River. Tom/Luke route off rib between Frenchman Coulee and Echo Basin shown in red.

Ice Age flood bar.
We're back on the Grant County side now - Road for scale on the giant flood bar at Echo Basin mouth.

Vantage Bridge over the Columbia River.
If you're not sure where we're at - This image shows the same bar and road beyond Vantage Bridge - arrow.

Ice Age Flood bar.
Apparently the huge bar is high enough to launch from.


Silica Road exit to Frencman Coulee.
If you're interested in the Ice Age Floods and have not visited Frenchman Coulee - Please take this I-90 exit and drive down to the river (dead end) It only takes a few minutes. If you drive down and are not impressed - I'll give you a beer (Offer limited to the two beers I found in Palouse River Canyon).

Grand Coulee petroglyphs.
What a treasure! The petroglyphs on this thing are incredible. This was my second visit to this rock (I'm not counthing the times I walked by it without noticing the special markings). The depth of the scratching is impressive.

She Who Watches petroglyph. Tsagaglalal.
She Who Watches (Tsagaglalal)

Petroglyphs are found throughout the scabland and Columbia Gorge


Visit the Columbia Gorge to view She Who Watches.

Trip Report from this area: The Dalles and "She Who Watches"


Columbia River petroglyphs.
Many petroglyphs were moved to higher ground when Columbia River dams were built.

Ginkgo State Park petroglyphs.
Petroglyphs shown in this photo are on display at the Ginkgo State Park visitor center.

Celebration Park petroglyphs.
Dozens of basalt boulders rounded by the Bonneville Floods near Celebration Park (Snake River canyon south of Boise, ID.) are marked with petroglyphs.

Lake Lenore Caves.
Lake Lenore Caves were carved by floodwaters from Glacial Lake Missoula. Early coulee residents used the many caves in this area for shelter and storage.

Missoula Flood pothole.
Numerous potholes in the area. These things were drilled into the basalt by tornado-like currents in the floodwater.

Lake Lenore Caves geocache.
This is where we parted ways with "Wisdom". He's in this pile of rocks at:

N 47° 30.727 W 119° 29.861


East Channel Lake Lenore.

Luke locates the Lk Lost N Time geocache. We're in the huge channel east of Lake Lenore.

Ice Age Flood scabland.
Textbook scabland development behind Luke.


Park Lake.
The frozen surface of Blue Lake was like glass. I think we both may have set 'personal best' rock throwing distance records.

Dry Falls visitor center.
Luke checks out displays at the Dry Falls State Park visitor center. Those are some impressive teeth!

Smithsonain Gold exhibit.
Luke likes science and seems interested in geology. Teresa, Luke and I visited the Smithsonian in November. Lots of 'Smiling Luke' photos from that trip but - he struck a serious pose in front of the gold display ... and did the same when standing next to Eddie Van Halen's guitar.

Scabland hiker.
Luke's favorite activity is riding dirt bikes with his Dad. I'm glad he doesn't mind a few slow-paced scabland hikes with his uncle.

Click below to watch Nick Zentner interview USGS Geologist Richard Waitt.

New and Interesting!!!



Richard Waitt (USGS) - Interview


If you have a few minutes - check out the new Columbia Gorge IAFI Chapter website. Chapter founder and president Terry Hurd is a good guy and works hard to help others understand and enjoy the Ice Age Floods story.

Tuesday, December 6, 2011

Starbuck via Hammer Grade

Plenty of December sunshine Sunday as I took a drive (and a few short hikes) to explore several Ice Age Flood features along the Snake River.

I'd been wanting to check out the streamlined Palouse hills near Hammer Grade Road (Cheney-Palouse Scabland Tract) and had also been interested in visiting a viewpoint along the Little Goose Dam Road (South of river). Dam crossings are not allowed on weekends so ... I ended up driving to the gate on the north end of Little Goose Dam and then backtracking to Washtucna Coulee, then south and around to Starbuck. Not a problem, I like it out there.

Before I get to the trip photos, let me add one taken last Thursday. Teresa and I made a trip to Ellensburg to attend the Ellensburg IAFI meeting [Speaker: Richard Waitt USGS]. I wish I could make it up to more of their meetings. Nick and Karl do a great job.

On the way, we made a quick stop south of Sentinel Gap to view huge field of boulders that settled out as floodwater entered the Pasco Basin.

[Click any image to enlarge]



Teresa and erratic boulder near Mattawa, WA. Sentinel Gap in the distance.

Back to Sunday's trip.

Palouse Falls bottom of falls pool.
Pretty good variety Sunday. Lots of streamlined Palouse hills, gravel bars and a quiet hike to the bottom of the Palouse River Canyon.

Streamlined Palouse Hill left by the Ice Age Floods.
Early morning along Hammer Grade Road. This area was once covered with rolling loess hills up to 250 feet thick. In major channels the Ice Age Floods removed huge amounts of loess (windblown silt), exposing the basalt bedrock. Many loess islands were left behind (like the one pictured above).
"Here are streamlined, prow-pointed and steeply scarped loessial islands 150 feet high" J Harlen Bretz

The Lake Missoula floods left streamlined Palouse Hills.
Wheat is grown for miles to the left of image. A ten mile wide flood tract exists to the right. [View South]

1. Hammer Grade Road.
2. Wheat field.
3. Scarped Palouse hill.
4. Streamline Palouse hill.

Palouse Hills.
View North

Same thing here. Flood-swept basalt and streamlined hills to west. Wheat country on the right.

Hammer Grade Road.
Hammer Grade is no problem when bare. Might want to think twice before attempting to descend through snow and ice.

Ice Age Floods scarped hills.
Flood-swept scabland and scarped Palouse hills. If you want to search for the missing soil ... Try looking in the Willamette Valley and Pacific Ocean.

Two photos below from Bruce Bjornstad


I sure like these shots. I'm impressed the farmer has maximized his wheat acreage by farming a loess island!

Palouse Hills
Surrounded by scabland.


Flood-cut channel through Palouse hills.

Palouse deer.
Large deer population along Hammer Grade.

Hammer Grade Ice Age Flood deposits.
Once you get to the bottom of Hammer Grade (near the Snake River), start looking for depositional features left by the Ice Age Floods.

[Hammer length: 10.5 inches]


Little Goose Dam Ice Age Flood deposits.
Exposed flood deposits near Little Goose Dam (Snake River). Note band of fine material that settled out during slackwater conditions. I'll add a few photos below that show similar slackwater band(s) exposed downstream at Lake Sacajawea Bar. Road in distance climbs to top of Little Goose Dam. Recreation area marked with "1".

Call 1-888-DAMINFO (1-888-326-4636) for Dam Crossing Info.

Little Goose Dam
Little Goose Dam - Army CE Photo

Red arrow marks exposed flood deposits shown in previous image.


Hammer Grade dwelling.
Hammer Grade structure.

Hammer Grade warning sign has been rotated and bolted.


Chief Washtucna watches over the coulee.


Photo by Steve Coffel (Florence, MT)


Steve recently sent me a few Snake River photos that led me to the Little Goose Dam Road overlook. I like the soft lighting in this one along with the cool fence!

Thanks again Steve and I hope we can get out for a hike next spring!


Map shows lower Hammer Grade Road, Old Vantage Bridge (Moved from Vantage area when Wanapum Dam built) and Starbuck, WA. The Old Vantage Bridge crosses the Snake River just below Palouse and Snake confluence.

Rawhide Bar and Grill Starbuck, WA.
Starbuck now has two restaurants.


Starbuck, WA and Little Goose dam map.
Little Goose Dam at top left. Interesting flood deposits are found along SR-261 near Starbuck. Steve's overlook is marked with camera symbol.

Mid-Canyon bar Snake River.
View downstream from overlook.

1. Huge flood bar. I'm trying to find a name for it.
2. Mid-Canyon Bar (J Harlen Bretz described this feature in 1928).
3. Mouth of Palouse River Canyon (right).

Bruce Bjornstad describes the Mid-Canyon Bar in his book On the Trail of the Ice Age Floods.

"Floodwaters rushing down the Palouse River cataract canyon plowed into the high walls of the Snake River valley, forcing the water to split and rush in opposite directions. Some floodwaters surged up the Snake River for 80 miles, all the way to Lewiston, Idaho, and beyond. The rest of the floodwater went down the Snake River, eventually emptying into the Pasco Basin."

Snake River gravel bar.
View east from overlook. Looks like the pit is active.


The Mid-Canyon Bar is 2.5 miles long. A tremendous amount of gravel has been removed from bar below the mid-Canyon Bar (note the giant current ripples that are about to disappear).

Little Goose Dam airport.
- WSDOT - Photo

Little Goose Dam Airport was built on a Snake River bar. The water behind Little Goose Dam (Lake Bryan - Max. pool 646.5 feet) covers much of the bar.


YouTube video uploaded by fazonsazar on Sep 8, 2007. Video shows Cessna 172 landing at Little Goose Dam and Lock on a windy afternoon in late August.

Tucannon Valley.
Please scroll back up about six images (Google Earth) and check out the Tucannon drainage. Huge volumes of sediment laden floodwater surged into this valley during Ice Age Flood events.

Ya gotta feel sorry for the beavers living on this stretch of river 15,000 years ago. Feeling safe living off the main Snake channel ... Then suddenly forced to ride out a 700 foot deep flood surge that came from a downstream direction!


Tucannon Valley - View west from Little Goose Dam Road (on the way to the overlook). FYI- There isn't an official "Overlook". Just pull over when Snake River is in view.


At least six rhythmites are visible at the Starbuck exposure. Approximatly 25 have been found in the Tucannon Valley.

Missoula Flood rhythmites.
Bruce Bjornstad explains that the coarse basaltic gravel between some of the beds may be material shed off the steep valley walls between floods.

Starbuck, WA Ice Age Floods rhythmites.
Use caution if you visit this area on foot. Motorists are dealing with curves and elevation changes ... probably not expecting pedestrians.

Ice Age Floods rhythmites near Starbuck, WA.
The last time I visited this location, a woman stopped to ask "Are you OK?". I don't think she had much of an appreciation for the flood feature I'd driven many miles to examine.

Ice Age Flood rhythmites draped over Columbia River Basalt near Starbuck, WA.
Ice Age Flood rhythmites and Columbia River Basalt. I'm standing too close!!! Good thing Skye Cooley thought enough to back up and capture a panoramic view of this exposure. See below.


Thanks to Skye for letting me use this amazing shot of Starbuck rhythmites draped over Columbia River Basalt. (Click to enlarge)

Check out some great shots at Skye's: Picasa Clastic Dikes Gallery.

Hammer Grade flood deposits from Little Goose Dam Road.
Now I'm on the south side of the Snake River - Looking at the first flood deposits shown above. The exposure between Hammer Grade and Little Goose Dam. You can see the slackwater band.

Lake Sacajawea Bar rhythmites.
Here's a shot of a similar slackwater band exposed downstream on the 400' tall Lake Sacajawea Bar.
Lake Sacajawea Ice Age Flood Bar.
A few images here from a visit to the Lake Sacajawea Bar earlier this year. The size of many Snake River gravel bars is impressive. Hard to image what happened along the Snake River between Pasco and Lewiston at the end of the last Ice Age. Usually the floodwaters raced down the Snake and into the Pasco Basin. Other times when Wallula Gap restricted the flow, floodwater rushed up the Snake River. During several intervals, the flow stabalized and fine material was allowed to settle out to form the slackwater bands we see today.

Red arrow points to Walker Bar.


Walker Bar along Snake River.
Walker Bar borrow pit.


Lake Missoula flood deposits.
Still looking at Lake Sacajawea Bar flood deposits.


Contact between flood gravel and slackwater deposits.
The drastic material change is cool. Some of these contacts are super sharp.


Snake River flood deposits.
Bruce Bjornstad has placed an interesting Geocache near this location.


Railroad spike for scale.

"The gravel pit excavated by the railroad here has a scarp 200 feet high. The gravel is unindurated and slides easily, so that the structure is difficult to decipher. But it is 99 per cent basalt." - J Harlen Bretz 1925

The streamlined hill shapes are often referred to as teardrop, ship-like or airfoil-like. Earlier this year I attended an Ellensburg IAFI chapter meeting and heard Vic Baker compare them to "A trout in a stream". I like that one.

Several excellent examples of streamlined Palouse Hills are visible from the intersection of SR-261 and the entrance road to Palouse Falls State Park.

"These hills consist of "islands" of loess that appear to float in a sea of basalt scabland. Their teardrop shape consists of a prominant steep prow on the upstream end and long tapered tails on the downstream end. This shape, which was repeated over and over again in the formation of streamlined sedimentary hills, is not a coincidence. During Ice Age flooding, the hills were streamlined so their length was usually about three times longer than their width; this hydrodynamic shape provided the least amount of drag to the floodwaters that formed them. - Bjornstad"
NASA Mars streamlined hills.
NASA has some impressive shots of streamlined hills on Mars. Scientist estimate flood volumes on Mars were 10 times the largest Missoula flood.

Scarped hills near Palouse Falls State Park.
SR-261 near the entrance to Palouse Falls State Park - The scarped Palouse hills aren't too far off the highway.


Palouse River Canyon - Smithsonian Museum.
Teresa and I were in Washington, DC the week of Thanksgiving - I noticed this Palouse River Canyon USGS photo in the Smithsonian National Museum of Natural History.

Cool! Franklin County in the Smithsonian.

View from bottom of Palouse River Canyon, Palouse Falls State Park.
- Palouse Falls -


Link to 2009 hike in this area.


Nice day. Too much driving and not enough hiking but still fun!

Merry Christmas! Tom



Glacial Lake Missoula floodwaters were responsible for most of the features pictured above; However, another large flood swept through this stretch of the Snake River about 17,400 years ago. Click video above to watch Nick Zentner interview USGS Geologist Jim O'Connor. Jim talks about the Lake Bonneville Flood at the 14 minute mark of interview.

Watch Nick interview other guests from the US Geological Survey and various regional organizations at Central Rocks.
"Central Rocks" aims to promote an appreciation and understanding of Washington geology - while also shedding light on research and teaching of CWU faculty.