Ice Age Floods Features - East Rim of the Grand Coulee

Photos from a September hike along the east rim of the Grand Coulee - between the "Million Dollar Mile" and Northrup Canyon. Bruce Bjornstad and I enjoyed the awesome Ice Age Floods features found along this 15 mile hike. Not sure of ownership in a few areas ... we tried to stay as close to the rim as possible throughout the hike.

Click any image to expand


Million Dollar Mile
This spendy one mile stretch of Hwy 155 in the Grand Coulee was built in 1948. The cut through the basalt became necessary as the Bureau of Reclamation filled Banks Lake.


Hiked from location marked as 7 to 4.
The Grand Coulee is considered by many to be the most remarkable legacy of the Ice Age floods. Today the massive coulee is used for off-channel storage of Columbia River water. A huge pumping station adjacent to Grand Coulee dam lifts water into the coulee. This water will either generate power as it returns to the Columbia River or flow south to irrigate crops in the Columbia Basin Irrigation Project as far south as Pasco.

1. Lake Roosevelt
2. Grand Coulee Dam
3. North Dam
4. Northrup Canyon
5. Steamboat Rock
6. Nespelem Silt deposits (white bank)
7. Million Dollar Mile
8. Dry Falls Dam
9. Dry Falls
10.Deep Lake


Geologist/Author Bruce Bjornstad hikes near an impressive basalt butte created by the Ice Age Floods.


Hiking south to north along the coulee rim.

The floods scoured out many saucer shaped potholes along the east rim. These are cool but I'm more impressed with the Deep Lake and East Lenore Channel potholes a few miles to the south. Bruce for scale.


The potholes hold water late into the season. A Google satellite image got us close to these potholes. We then followed animal trails to go from one pothole to the next.


The guy on the right - that didn't want to pose - looked like a nice buck.


Half of this pothole disappeared as the Grand Coulee widened.


Looking north up the Grand Coulee. Basalt knob on east rim shown in next image.



Photo by Bruce shows Steamboat Rock to the north. Tom hiking along rim at right.


This Bureau of Reclamation photo shows Grand Coulee Dam and the upper Grand Coulee.

1. Grand Coulee Dam
2. Lake Roosevelt
3. Pumping Station
4. Feeder Canal
5. North Dam
6. Steamboat Rock


Early photos show the Grand Coulee looked much different prior to the construction of Grand Coulee Dam. Photos from top show Steamboat Rock, BOR employees walking through wheat fields on the coulee floor and the clearing of sagebrush.

To view hundreds of photos taken during the construction of Grand Coulee Dam and the Columbia Basin Irrigation Project, visit Central Washington University's Rufus Woods Collection.

This band of palagonite formed when lava flowed into water. -Photo by Bruce ...Tom trying not to slip on the mini marbles.

Columbia River Basalt Group


Bruce standing on ring dike near the coulee rim.



Google satellite view of the same ring dike.
-Use your mouse to navigate satellite view-


East coulee wall
1. Hwy 155
2. Steamboat Rock State Park entrance
3. Northrup Canyon


Here's a shot for the three or four people out there who enjoy longitudinal groove images.


Looking north to Castle Rock (flat top).


Steamboat Rock in the upper Grand Coulee. The Nespelem Silt deposits on the coulee floor can be examined along the lake shore.


The white banks below Steamboat Rock sure are interesting. This view from the coulee rim shows the best exposure of Nespelem Silt in the coulee. These lake deposits were probably laid down in Glacial Lake Columbia between (or after) the megafloods.


Wave action along the shore of Banks Lake disturbs the silt deposits.


Here are a couple of shots taken during a visit to the Nespelem silt deposits in the spring. The petrified doughnuts found on the beach make me hungry.


Bruce views a section of the Nespelem silt deposits. The bank is unstable in places ... Use caution if you explore this area ... Not a good place to visit with children!!!


In some sections of the Nespelem silt deposits you can follow the alligator skin pattern into the bank. Ice age mud cracks!




Back to the coulee rim hike ... Another shot of the Nespelem silt deposits. The white banks shown in previous images are along the far shoreline in this photo. Note the giant current ripples.


Bruce views the flood-swept east rim of the Grand Coulee.

Map created by Bruce shows ice lobe that diverted Columbia River and floodwaters from Glacial Lake Missoula down the Grand Coulee.

At times the ice lobe blocked the Columbia River creating Glacial Lake Columbia. This photo from another trip (a few miles NE of Northrup Canyon) shows Glacial Lake Columbia shorelines cut into the hills 1,000 feet above the surface of Lake Roosevelt.


Haystack Rocks (large pieces of basalt) scattered above the west rim of the Grand Coulee were left behind when the ice sheet melted.


Here's a shot of a huge haystack rock west of the Grand Coulee (wife Teresa left of rock). Yeager Rock sits next to Hwy 172 east of Mansfield.


View Larger Map
Tough place to farm! That's Yeager rock upper left. Use mouse to view more debis left by the ice sheet.


One of the erratic boulders stranded on the east rim of the Grand Coulee. Not as many granite boulders on the east rim compared to what you find on top of Steamboat Rock.


Photo from another hike shows one of the many granite boulders stranded on top of Steamboat Rock. View down the Grand Coulee.


Another of the large erratics on top of Steamboat Rock. View shows mouth of Northrup Canyon (1) and Whitney Canyon (2) along east rim.


Northrup Canyon from Steamboat Rock. Plenty of history in this canyon.


Northrup Canyon Structures.

It was getting pretty late when Bruce and I reached Northrup Canyon. Great day with perfect weather.

Open link to view map of Coulee Corridor


View Larger Map

Spring Coulee (East Rim)

- Click any image to expand -

Looking northwest to Billy Clapp Lake from road.Farming operation above trimline - top left.


No violations today ... I was unarmed and alone.

Last month I posted a few photos and text after a hike down the west side of Billy Clapp Lake.

See: Billy Clapp (West Side)
As I walked the west side in October, I was looking through binoculars at some of the flood features above the east shore and decided that I'd need to get a closer look. Saturday I noticed that Accuweather had a sunball symbol on Sunday ... So off I went (I wish I'd have looked at the numbers they had next to the sunball). When I started hiking it was 18 degrees ... Gloves and a warmer coat would have been nice.

The approach I took is described by State Fish & Wildlife as: "A primitive parking area on the east side of the Billy Clapp Reservoir that is about two miles from the west end of county Road 26 NE off of county Road Q NE."


No shortage of deer between Wilson Creek and Billy Clapp Lake.

I was surprised at the number of deer, ducks and geese I saw during my hike. The State doesn't seem to think much of the area as a refuge. Paragraph below from Washington State Department of Fish and Wildlife site. The two-page ownership map it provides is pretty good. - See link below.

Billy Clapp area ownership map
Columbia Basin Wildlife Area

The Billy Clapp Lake unit is 4,000 acres along what was originally called Long Lake Reservoir but renamed in honor of one of the originators of the Columbia Basin Irrigation Project. The natural coulee was dammed on the lower south end (Pinto Dam) to create the reservoir. Water cascades into the upper end of the reservoir from the Main Canal creating Summer Falls. Basalt cliffs of varying heights encompass the reservoir. Most of the shoreline is too steep and rocky to support wetland or riparian vegetation, and the uplands are a mix of poor quality gravelly soils and basalt outcroppings. Vegetation varies from the fire-caused cheatgrass or bunchgrass communities to native woody shrubs on talus slopes. BOR maintains public parking, and boat launching is available on the north end of the lake. The Stratford Game Reserve encompasses nearly all the public land in this unit. Originally designated to provide a resting area for migrating waterfowl each fall, public use and changing migration patterns have made the Game Reserve less effective.

From the Grand Coulee

THREE ICE AGE FLOOD CHANNELS

Not all of the Grand Coulee flow entered the Quincy Basin via Lower Grand Coulee. Water that escaped the Grand Coulee cut channels around High Hill and Pinto Ridge. These channels carried substantial flows and became known as Dry Coulee and Spring Coulee (The reservoir created in Spring Coulee is today named Billy Clapp Lake). Floodwaters flowing through Spring Coulee fed into the Crab Creek channel prior to entering the Quincy Basin.

As stated in the October post - J Harlen Bretz called Spring Coulee:

"A fine scabland canyon with castle-like buttes, lateral subsidiary canyons, and cataracts notching its walls"


Bureau of Reclamation Benchmark.

Between 1946 and 1948 the Bureau of Reclamation constructed Pinto Dam at the south end of Spring Coulee. The Coulee is one of many Ice Age Flood features used by the Bureau as part of the Columbia Basin Irrigation Project.

Surveyed by the USBOR 10 years prior to Pinto Dam construction.

It was pretty cool to take a few minutes and think about the surveyors walking the Ice Age Floods region in the 1930s. In his book "Grand Coulee Harnessing a Dream"- Paul C. Pitzer describes the surveyors searching the channeled scablands of eastern Washington for potential storage reservoirs, dam sites and canal routes.

Benchmark - GPS
N 47°28.910'
W 119°14.530'

The features I was most interested in on this side of the coulee were several potholes and a group of "Drumheller" type channels just east of the potholes.

The potholes were formed during the Glacial Lake Missoula flood events that swept over eastern Washington as recently as 15,000 years ago. Powerful whirlpools (sometimes referred to as underwater tornados) known as kolks, scoured out these holes.

WIKIPEDIA DEFINES KOLK: (also known as colc) is an underwater vortex that is created when rapidly rushing water passes an underwater obstacle in boundary areas of high shear. High velocity gradients produce a violently rotating column of water, similar to a tornado. Kolks are capable of plucking multi-ton blocks of rock and transporting them in suspension for some thousands of meters.

In his book "On the Trail of the Ice Age Floods", Geologist Bruce Bjornstad explains the creation of Rock Basins and Potholes: "Fast-moving floodwaters passing through scabland channels further gouged into the basalt, scouring out rock basins and augering deep holes into basalt. Like a powerful vacuum cleaner, floodwaters actually sucked up all the loose material off the land surface, including huge columns of basalt, taking advantage of any weakness in the rock, such as fractures."


Google Earth image with pothole ID numbers I'll use below.

To view image of pothole #4, you'll need to open the October post and scroll down to the pothole image.

Remember ... You can click image to enlarge.


Pothole ID #1

The picture doesn't do this pothole justice. This is one fine pothole! I'll return in the spring and try to get a better shot as the scale just doesn't show here.

Pothole ID #2

Pothole ID #3

During our lunch stop on the October trip, we noticed a "hanging pothole" on the other side of the coulee. Erosion of the main channel has opened up one side of the pothole. Future megafloods will finish the job and remove all traces of this pothole before going after potholes #1 and #2.

Many shallow potholes are found in this area.

These smaller kolk carved basins seem popular with the local wildlife. Game trails lead to each of them.

I'll embed a Google Map at the bottom of this post. If you switch the map from Terrain (TER) to Satellite (SAT) and zoom in, you'll be able to search the area and find many more potholes on the bench east of Billy Clapp Lake.


Several nice mesas near the lake.


A smaller version of "Hat Rock".


Hard to hide with those pointy things sticking out of your head.


Google Earth image shows Giant Current Ripples above Billy Clapp Lake


For scale you can open the October post where I posted an image of Bruce Bjornstad standing on one of the ripples shown in this shot. The mix of farmland, ripples and a massive flood channel remind me of a similar spot closer to home ... see photos below.



Giant Current Ripples in Washtucna Coulee -
Note farmer on tractor at top left.


Same shot but a little wider angle. Huge flood bar being removed at coulee floor. If you look to the right of the quarry there seems to be one ripple mark left.

Another set of Washtucna Coulee giant current ripples


Borrow pit in ripple-covered flood bar exposes layer of windblown loess deposited since the Ice Age Floods.




South of the coulee along Highway 28 a historical marker gives a brief history of the area:

HISTORY OF THE STRATFORD AREA
Indians camped along Crab Creek in Stratford to gather roots and other food. The main Indian trail came past Stratford across the creek. The Indian trail branched here & one went past Pinto Dam. LT Symons came past here while laying out military wagon road from FT Walla Walla to Camp Chelan in 1879. Old wagon road from Waterville to Ritzville came past here in 1888. Railroad built in 1892. Early apple orchards were irrigated from Brook Lake in late 1890's. Pumphouse still standing. Stratford platted in 1903. Crab Lake drained by local pioneers in 1909 for farming purposes.
Grant County Historical Society