Saturday, June 29, 2019

Kootenai Falls

This isn't really a beach. It's actually not a beach at all. But there's moving water and geology, and if you're paying attention, ripples left in the sand by shallow water waves a mere 1500 million years ago.

Kootenai Falls is one the few big, unaltered drops left on any of the large western rivers. Most have been lost to dams and reservoirs, for hydropower and irrigation. Even those that haven't been completely submerged have often been drastically changed by structures and upstream diversions. 


The falls drop over resistant beds within the incredibly thick Proterozoic Belt Supergroup. The photos capture some of the extensive ripple marks, but unfortunately, none of the stromatolites (fossilized mounds formed by layered growth of cyanobacteria - a very, very long time ago) that are also exposed well near here.

Here's an early post on Gravel Beach that featured similar rippled Belt Series rocks, albeit ones found now on Puget Sound: Picnic Point 2007

And here are links to some other waterfall posts, all over at hshipman (waterfalls tend to find themselves on those pages more often than here on Gravel Beach):

Kootenai Falls: September 2012 (a previous visit)
Shoshone Falls: June 2012, September 2017
Great Falls: September 2017
Thompson Falls: September 2014


City Beach is located at the south end of Whitefish Lake, about a mile northwest of town. The sand and gravel beach may be natural, although I suspect it's been improved upon - if only because there simply aren't similar looking beaches elsewhere along the lakeshore. There are beaches, at least where the shore is oriented into the waves, but they are not as wide as this one.


A cluster of large boulders in shallow water creates a distinct inflection in the shape of the beach and may help segregate the more gravelly beach in front of the wall to the east from the sandier beach toward the boat launch.

Saturday, June 22, 2019

Lake McDonald

I suspect this is the same beach I posted pictures from several years ago (Gravel Beach: Sept 2012), although there are several fairly similar beaches along this stretch of Going to the Sun Road. The lake seemed a little higher this year and was encroaching into the trees in a few places along the shore. I don't think the level of the lake is controlled - the outlet, McDonald Creek, appears to be free-flowing - but it makes sense flows and water levels would be higher in June than in September.

There was a neat little recurved spit - looked a response to winds blowing west down the lake.

Most of the bedrock in Glacier belongs to the Belt Supergroup (a very thick stack of very old Proterozoic sedimentary rocks). The red and green argillites are widespread and when eroded by time and glaciers, yield red and green gravel, which waves shape into these nice little beaches.

Thursday, June 13, 2019

West Beach

This was pretty much the best possible place (and conditions) to end a field trip on my last day in the field as a professional! The concrete artwork was colorful in the sunshine. The beach provided a great contrast to the three other beaches we'd already visited earlier in the day (Custom Plywood, Bowman Bay, and Cornet Bay). And after a fairly minimalist geologic overview, the participants went back to throwing stones and climbing on the logs until we all had to run off to catch our ferries.

West Beach: February 2013

While the fulcrum of my work-life balance is about to shift dramatically, I plan to continue Gravel Beach. This year has been a slow one on the blog and that may not pick up right away - it has been a distracting few months and my summer and fall will likely be in the mountains and the Interior (not so many beaches). And finally, I have big issues with the platform: Blogger is not very mobile-friendly. The blog takes a lot of time (at least when I'm posting much). And Google has put virtually nothing into supporting it for years. I'll keep playing around with other sharing options - some of which are linked over on the right (desktop version) - and will certainly let folks know if I decide to make big changes.