Lost Lake, Montana

Lost Lake – travel story from Polly

     My second trip to Lost Lake began on a misty morning in June.

     A cool wet forecast in the Highwood area sent me packing wool sweater, and a rain jacket.

      But, I wasn’t as finely prepared as my guide, Ron Long, EMT, volunteer fireman, and historian par excellent, well known for his research of the rugged beauty of the Shonkin Sag, Lost Lake, and the Square Butte area.  A trail of waterproof footwear and beverage coolers awaited my arrival in Long’s driveway just off the highway straddling Highwood.

     Long will trod destinations within miles to share his love of his rural residence.  His excursions are often accompanied by others who share knowledge.  We were fortunate to be in the company of Chris Croff, a well traveled geologist, now living in the Monarch area.  Though Croff had previously not explored Lost Lake, he was well aware of the area he described as “glacially bribed,” and geomorphologically a “unique area.”

     He is not exaggerating.

      It’s old news.  Lost Lake, about 70 miles northeast of Great Falls, is the remnant of an ancient sea that roared during the Pleistocene (ice age) thousands of years ago.  A glacier advanced and formed a series of glacial lakes along the Missouri River and its tributaries. These lakes were confined by highlands to the east.  (For instance, glacial Lake Great Falls formed west of the Highwood Mountains.)  Eventually, however, the water level raised high enough to spill over the natural barriers and carve out a new channel.  Today, this abandoned channel is known as the Shonkin Sag, allegedly the Blackfeet word for the Highwood Mountains, or an adulteration of one of the town’s early settlers, John Shonk.

     The Shonkin Sag happened when one of the continental glaciers melted scooting snow and rain down.  That dammed the Missouri River which was hundreds of feet deep.  The dam became high enough that it flowed on the face of the glacier and formed this area.  The soil on one side of the valley was dumped by the glacier which included rocks.  On the other side there was a sea bed, the bottom of which was shale.  Eventually, the decayed mountains eroded down to the present size to get rid of the volumes of the mountains.   Deep within the earth, the molten magma melted, and changed the composition basically to a soup that rose to the surfaces picking up minerals like potash, and feldspar . Shoved under the mountain because of its thickness, the magma intruded up. It expressed itself when it vented to the surface  (volcano) and it left an unusual rock: Shonkinite.

    “Shonkinite is relatively rare, found only in a few places around the world,” Long told us as we turned onto the Shonkin Road.

     He pointed into the distance to the grand and picturesque Square Butte and Round Butte where vertical rocks encompass the land surface and form different linear patterns.  These are intrusive rocks, or laccoliths of Shonkinite, that form a flat line feature with more vertical extent.

     Already, I found myself viewing hills and valleys in a new way, encompassing new vocabulary.  Part of this region’s secret is that people look at the landscape and don’t understand what they are seeing.

     “Once you have the knowledge and pursue the rhetoric, then you have something you can walk away with,” said Croff.

      As we approached the Shonkin Sag several miles on Shonkin road, the Sag ran east and went parallel to the road.  Now it turns and starts off to the north.  Here, you can see a valley where the river was dammed and washed out an elongated depression between upland hills.

     A rocky slope revealed a gravel pit filled with Shonkinite: dark black or grey stones with grey speckles.  This is one pile of rocks: millions of tons of gravel from a north flow of water that deposited it.

     Long pointed to explain that “when the glacier diverted the Missouri River, it didn’t always run in one channel.”  “It pushed the river out further east of here into several other channels.” 

     From here, we approached the channel where the river ran and formed Lost Lake.  There are appearances along the way of volcanic dikes, outcroppings of rocks that were formed by the river channel.

    A sweeping green landscape plunged us into a canyon along Shonkin Creek filled with bleached sandstone and granite.  Early summer turns these lush hills to a vibrant green, dotted with yellow balsamroot. And, the purple blossoms of Russian lilac sweetly invaded our geological navigation.  As a kid, Long fished along this rock dike, bringing home a fine catch of trout!

     Lost Lake was our destination, but a series of other lakes lie along the Shonkin Sag.

     “They are dead lakes like the Dead Sea with an accumulation of salt,” explained Long. 

     “When they dry up they leave a salt residue late in the summer.  The salt residue is evident throughout this area because when the glaciers melted and formed shale, that was about three per-cent salt, the source of the saline seeps that have caused so much trouble in this part of the country.  Shale is near impermeable.  The water doesn’t sink into it, but evaporates.”

     Long motioned to the slumping hills ahead of us, mostly made of shale with a thin layer of top soil above that shale. The shale has bentonite in it, which when the soil gets saturated, (especially in the spring) it slips, and makes the benches along the hills.

     “Even in my lifetime I’ve seen it,” he said, stopping to show us the railroad track just ahead which was covered with sliding earth from the slump.

    After patiently following an antelope down the dusty road, we turned into a small parking pullout.  

     A long walk across a field, led us to a secret valley in the depths below.  Here was Lost Lake, approximately one mile long, surrounded by laccoliths and the dark outcroppings of Shonkinite formations.  From our vantage on a steep promontory, the bluish green water was quiet and somewhat foreboding.  The lake remains its old self, tied to the ancient past with tales sunk in the deep still waters, hidden from most of mankind.  The unspoiled prairie around the perimeter gives way to numerous wildflowers lingering with blossoms of: lupine, wild rose, prickly pear, and sandlily.

    “Can you just see the Missouri River dropping over these rocks,” pondered Long, as we stood marveling at the experience and exploration of a long forgotten world.

     This was why we had made the day long journey to experience and savor such a geological wonder. The adventure was worth a sustained pause to soak up as much of the strata as we could.  Now, we understood why the guest book at the Four Sisters Ranch in Square Butte included a long roster of famous geologists who had come to this area to do research and attend the 1989 International Geological Congress.

      Among other things, our tour brought us into the town of Square Butte where we stopped for a delightful lunch at the Square Butte Country Club.  We pulled up to the lone parking meter, and stepped into the tiny bar and restaurant.  Chef Amy was in the back baking desserts for the Saturday night hoedown, but she came out to review the menu items which included tasty burgers, homemade soup, Rocky Mountain oysters, and chicken livers. 

     Before departing Square Butte, we stopped to view the old jail house constructed in the late nineteenth century of Shonkinite.  The square block stones and iron bar windows remain touchstones to the past and a testament to the local construction one hundred years ago .

      Focused on the idea of an unusual day escape, there is much pleasure and novelty of encountering newfound geology, and something old and ancient, like Lost Lake, and the historical surrounds.

     Lost Lake is located on private property.  Occasionally tours are available.

 Call:  Ron Long @ 406-733-5321.

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