Montana’s Best Kept Secret — Lost Lake

After a beautiful Sunday morning spent exploring Fort Benton, Montana, we decided that we were up for a real Montana off the beaten path adventure. Something simple. Hmmm, what could we do?

What if we visit the geological epicenter of the end of the last Ice Age? Yep, you can really do that in central Montana!

Everyone in Montana has a Gazetteer (detailed local atlas) under her car seat, so we pulled it out and found Lost Lake on the map. We headed down 20 miles of stone roads through a pastoral landscape. Along the way, we saw antelope, trophy whitetail deer, golden eagles, and wheat fields as far as we could see.

Since this is such an important geological site, I expected that we might at least find a sign explaining the history that had happened here. In most places, this would be likely be a state park, or maybe even a national monument. But no, we found a tiny sign from the rancher who owns the land, sharing his land with us and telling us to be careful. This is what makes Montana so special.

I’m no geologist, but I will never forget what I saw at Lost Lake. This is the site of a dry falls that was the catastrophic overflow of a massive glacial lake that happened at the end of the last Ice Age (~80,000-200,000 years ago).

“As Ice Age succeeded Ice Age, the ancient Missouri River — which flowed north to Hudson Bay before the continental glaciers pushed its channel ever farther south — was dammed at different points, forming lakes of various sizes and shapes.*”

Imagine drying up Niagara Falls and seeing what sort of massive destruction it has created to the bedrock below. That’s Lost Lake!

“To imagine that volume of water, consider this: given the depth of Lost Lake, the falls probably dropped 300 to 350 feet when the Shonkin Sag was brimful and water poured over the top.  At 300 feet deep and half a mile across, the Dry Falls would have been just about double size of the largest cataract at today’s Niagara Falls.*”

The ancient igneous rock that also forms the nearby Highwood Mountains and its interaction with a cataclysmic event at the end of the Ice Age forms an otherworldly landscape, one that you have to see to believe.

And all of this sits quietly in a rancher’s field in the middle of central Montana.


P.S. On our way home, we found Elmo’s Highwood Bar in Highwood, Montana. Great food. Great people. An authentic Montana experience. Don’t miss it!

*All quotes from Montana’s own Niagara Falls, Last Best News, February 15, 2014

Directions: We think the easiest access is from Great Falls. Take 87/200/3 east. North (left) on Montana 228 past Highwood. Right on Shonkin Road W (gravel). Right on Shonkin Road (gravel). Left on Lost Lake Road (gravel). You will pass a large alkali lake on your left and soon after you will see a small pull-off on the right for Lost Lake. It has a small white handmade sign: “Private property. Walk from here. Enter at your own risk.”



Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s