Mary and I traveled west from the Big Bend of the Flathead River towards Hot Springs, Montana, on the Little Bitterroot Road. Along the way we saw hundreds (?) of Mountain Bluebirds and what seemed like a myriad of bluebird houses adorning fence posts and power poles. We turned north into the lower end of the Little Bitterroot Valley and drove for a few miles before turning west on a connecting road, crossing the valley, and finding the north end of the Big Gulch Road. We drove the Big Gulch road up and over the drainage divide into the Camas Prairie Basin. My plan was to try and get a westward view of the mega-ripples from above the valley floor. Fortunately, Mary had fallen asleep at the time we passed the "Minimally maintained road, travel at your own risk." sign, so we really didn't need to talk about that.

Here is a link to a satellite view of the mega-ripples https://www.google.com/maps/@47.5341718,-114.5973815,4952m/data=!3m1!1e3.

The mega-ripples formed during one or more catastrophic discharges from Glacial Lake Missoula when ice-dams, likely located near Sand Point, Idaho, failed. The lake(s) drained rapidly and tremendous water volumes flowed over the bedrock divide (Markle Pass), eroding it and depositing debris into the north end of the Camas Prairie basin. 

The photo below is a view to the west from near the divide between the Camas Prairie and Little Bitterroot Valley on the Big Gulch road. The mega-ripples lie mostly east-west here and are shown best by snow drifts in the swales between the ripple crests. Water flowed from right to left in this photo.

Camas Basin Ripples IIGlacial Lake Missoula catastrophic flood ripples, Markle Pass, Montana. View west from Big Gulch Road. April 5, 2019
The photo below shows Markle Pass (at left near the top of the slightly green hills--you can see Montana Highway 382 going up the pass). The relatively low bedrock divide crosses the photo above the mega-ripples. Again, water flowed from right to left as the glacial lake drained. Ripples in the distance are marked by snow drifts; ripples in the foreground are bare. The green hill in the mid-ground is a deltaic gravel deposit formed by water that flowed through a low point a couple of miles east of Markle Pass. Camas Basin RipplesGlacial Lake Missoula catastrophic flood ripples, Markle Pass, Montana. View west from Big Gulch Road. April 5, 2019

The final photo is a view to the south from the Wilks Gulch Road, about one mile east of Highway 382. The trees at the far left are the same trees seen in the photo above to the left of the green hill. We are looking 'downstream'. Parallel horizontal lines on the tree covered hill (far left middle distance) are strand lines (beaches) made by the glacial lake. 

Camas Basin Ripples IIIGlacial Lake Missoula catastrophic flood ripples. View is south fom Markle Pass, Montana. April 5, 2019 Click the images to see them in the Geology and You Gallery. Go to http://twpattphotos.com to see today's Home Page Slide Show.