-Dry Falls Lake upper left-
Dry falls is one of the most well known features created by the Ice Age Floods. This great cataract group is primarily made up of Dry Falls, Monument and Deep Lake coulees. The two best known lakes immediately below the precipice are Dry Falls Lake (Bretz refers to this lake as "Falls Lake" in his papers) and Deep Lake.
The State describes Sun Lakes-Dry Falls State Park as a 4,027-acre camping park with 73,640 feet of freshwater shoreline at the foot of Dry Falls. Dry Falls is one of the great geological wonders of North America. Carved by Ice Age floods that long ago disappeared, the former waterfall is now a stark cliff, 400 feet high and 3.5 miles wide. In its heyday, the waterfall was four times the size of Niagara Falls. Today it overlooks a desert oasis filled with lakes and abundant wildlife.
Umatilla Rock is the long slender island in the big horseshoe shaped cataract system. Dry Falls Coulee on left, Monument Coulee on Right. Deep Lake Coulee joins from the far right. The State Park's northern boundary is confusing. The ranger in the visitor center has tearoff maps available.
I parked at what looked to be a new turnout or small parking area along the west side of Umatilla Rock and found a faint path through the talus. Near the top I had to use both hands to access a ledge or two before reaching the top. I don't think this is an official part of the Umatilla Rock trail. Hazards encountered by those hiking in the park seem to be listed on all trailhead signs.
The top of Umatilla Rock is pretty cool. The Ice Age Floods really swept this thing off flat.
Looking off the east side of Umatilla Rock, one views huge basalt blocks scattered over the western portion of Monument Coulee.
This basalt shelf in Monument Coulee is pretty cool. It sits just downstream from a large depositional feature and has been drilled from above by a kolk (underwater tornado/whirlpool) during an Ice Age Flood event. The feature left by the kolk is known as a pothole.
According to the Wikipedia page: "The Lemhi Shoshone believed the small red core found in the upper taproot had special powers, notably being able to stop a bear attack."
The hike into Monument Coulee along the east side of Umatilla Rock is nice when the wildflowers are blooming. The huge basalt blocks shown in earlier photos are pretty impressive when viewed from the coulee floor.
An interesting spire stands at the south end of Umatilla Rock.
The same basalt blocks that were mentioned above. Several similar clusters are found nearby.
North end of Umatilla Rock. Fisherman on Dry Falls Lake at right.
This is one of the most amazing areas in the Channeled Scablands. Every time I visit the Deep Lake area I find more incredible Ice Age Flood features.
In his 1932 publication "The Grand Coulee", J Harlen Bretz included images and description of the "pothole-riddled ledges south of Deep Lake". Bretz noted that some of the holes are 40-50 feet deep.
The Ice Age Floods ripped out and removed tremendous amounts of basalt from the Upper and Lower Grand Coulee. There are a few sheltered areas where the floods deposited material ... Small gravel bar on opposite side of coulee. Check out all those potholes!!!
A few of the Deep Lake potholes with a blue pickup truck for scale.If you visit the Washington State Park's Centennial Page you can open a copy of the Interpretive Master Plan
for the Ice Age Floods in Washington State Parks
The document describes this group of potholes:
"Another spectacular feature is a tight cluster of the deep potholes beyond Sun Lakes just west of Deep Lake. These potholes lie along the valley bottom and require only a 5-10 minute walk from the road."
CAUTION: I'd like to add that a fall into one of these potholes could be fatal!!!
I actually measured one of the Deep Lake potholes last year. This illustration is pretty close to scale. I'm 5'10, the pothole is 48' deep and 76' across.
One of the many bedload carried erratics scattered through the park.
This pothole just above the brink of the falls has a nice shape but the water quality doesn't look good. Nasty looking layer of algae.
Red Alkali Lake and Green Lake in upper Monument Coulee.
I almost stepped on the female killdeer tending these eggs.
Interesting pothole gouged into a weak section of the basalt.
Google aerial view of the same pothole. Zoom out or pan side to side to view location of pothole shown in the previous image.
The huge basalt knobs pictured above are between Monument and Deep Lake coulees. The cover of one of my favorite books about the Ice Age Floods shows the same feature viewed from a different angel. David Alt's Glacial Lake Missoula and it's Humongous Floods is available at the IAFI Store.
The Dry Falls area is one of the best locations to view Longitudinal Grooves carved by the floods. They sure stand out this time of year when the grooves are filled with blooming wildflowers. 
The State Park's Visitor Center at Dry Falls houses excellent displays that describe the creation of the Lower Grand Coulee. Videos that explain Lake Missoula and the Ice Age Floods are also shown.I'd be willing to provide a couple gallons of basalt brown paint to the State Parks if they ever decide to paint the south wall of this ugly structure. You can see the big white box for miles.
On previous visits to the Dry Falls overlook, I failed to notice this small flood tumbled erratic placed on one of the stone walls.
The Dry Falls overlook has been a popular spot for years. Photo above from the Rufus Woods Collection (Housed at Central Washington University), shows a woman photographing Dry Falls in 1940 (Umatilla Rock in the distance).
Another image from the Rufus Woods collection. The caption posted for this 1946 shot states: "F.A. Banks, Supervising Engineer at Grand Coulee Dam explains features to Secretary of Interior Krug and party at Dry Falls near Coulee City, Wash."
Dry Falls viewed from the visitor center along SR17.
This set of contour lines is pretty good evidence that the Ice Age Floods were a powerful force.
Sunday, June 7, 2009
FIELD TRIP: Dry Falls and the Lower Grand Coulee (led by Karl Lillquist, Coulee City native!)
8:00 am - 6:00 pm (carpool from Hebeler Hall parking lot)
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