Near Lolo in Missoula County, Montana — The American West (Mountains)

Taking The Waters

Photographed by Barry Swackhamer, June 16, 2026

1. Taking The Waters Marker

Inscription. When William Clark "discovered" Lolo Hot Springs on September 13, 1805 was already a popular bathing site. ,,, passed Several Springs..., and below one of the[m] Indians had made a whole to bathe... Several roads led from these Springs in different derections... On the return trip in 1806, the expedition planned a camp at the hot springs so the travelers could enjoy a rare bath. ,,, passed Several Springs..., and below one of the[m] Indians had made a whole to bathe... Several roads led from these Springs in different derections... On the return trip in 1806, the expedition planned a camp at the hot springs so the travelers could enjoy a rare bath.

Why a hot springs here?
Lewis may have been standing near here when he noted.... these warm springs are situated at the base of a hill of no considerable hight on a N side and near the bank of travellers rest creek ... these springs issue from the bottoms and through the interstices of a grey freestone rock, the rock rises in iregular mass clifts in a circular range arround the springs on their lower side... - Meriwether Lewis, June 29. 1806 The hot

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water flowing out at the base of the rocks in front of you began as rain and snow that fell on the surrounding mountains. It follows near-vertical fractures in the rock deep underground. At perhaps 2.5 km/1.5 miles deep, the natural heat of the earth raised the water temperature about 83ºC/181ºF. This heated water rises to the surface along other fractures. On the trip back up, the water loses heat [to] the cooler rocks, so that the temperature at Lolo Hot Sprigs is about 44ºC/111ºF.

A regional view
You are at the north end of the Idaho Batholith, a very large mass of granitic rocks that started forming in the Cretaceous Period, more than 90 million years ago. At that time this spot was near the western edge of North America. For over 30 million years, colliding tectonic plates caused episodes of rock melting. The Lolo Batholith appeared late, when that hot expanded crust was beginning to pull apart.

The Lolo Batholith rocks...
The rock here is granite of the Lolo Batholith. It crystallized from a fiery hot melt about 50 million years ago. The heat of that event is gone now and erosion has uncovered the granite, It

Photographed by Barry Swackhamer, June 16, 2026

2. Taking The Waters Marker

Note the batholith rocks in the backgrounds.

fractured, first as it cooled and later by release of pressure as the rock above it eroded.
A very close look
Glassy gray quartz and tan-pink feldspar crystals in the granite are the source of the Hard Core Grit Captain Clark described (Sept. 13, 1805). Most of the crystals have rough interlocking edges because they had to compete for growing space. Because this granite melt crystallized quite close to the earth's surface, some small gas pockets formed. Crystals that grew into these gas pockets formed perfectly!

... I tasted this water and found it hot & not bad tasted... I put my finger in the water, at first could not bare it for a Second... William Clark

[The rest of this marker is too badly damaged to transcribe]

Erected by University of Montana Western.

Topics and series. This historical marker is listed in these topic lists: Exploration • Natural Features • Parks & Recreational Areas. In addition, it is included in the Lewis & Clark Expedition series list. A significant historical date for this entry is September 13, 1805.

Location. 46° 43.542′ N, 114° 31.966′ W. Marker has been reported unreadable. Marker is

Lolo Hot Springs Pool image. Click for full size.

Photographed by Barry Swackhamer, June 16, 2026

3. Lolo Hot Springs Pool

near Lolo, Montana, in Missoula County. It can be reached from U.S. 12 near Fish Creek Road (County Highway 32), on the right when traveling west. Touch for map. Marker is at or near this postal address: 38500 U.S Highway 12, Lolo MT 59847, United States of America. Touch for directions.

Regionally, this marker is in Western Montana,

in Glacier Country,

and in Greater Missoula.

It is also in the American Mountain West

and in the Lewis & Clark Corridor.

Globally, it is in North America,

the Rocky Mountains,

the Western Hemisphere,

the Western World,

and the Anglosphere.

Historically, it finds itself in what was once Rupert’s Land

and also the Louisiana Purchase.

Other nearby markers. At least 8 other markers are within 10 miles of this location, measured as the crow flies: Soldiers as Naturalists (approx. 1½ miles away); Cycles and Circles (approx. 4.4 miles away); Lewis and Clark Route (approx. 6.2 miles away in Idaho); Lolo Summit (approx. 6.6 miles away in Idaho); Lewis and Clark (approx. 6.6 miles away in Idaho); Nez Perce Trail (approx. 6.7 miles away in Idaho); Lolo Trail Crossing (approx. 9½ miles away in Idaho);

Lolo Hot Springs image. Click for full size.

Photographed by Barry Swackhamer, June 16, 2026

4. Lolo Hot Springs

Everybody Stopped Here!
Indians, explorers, fur traders, surveyors, prospectors, soldiers, hunters, fire fighters road builders, fishermen, vacationers.. everybody stopped here.. and now... YOU!
(just wish the photos weren't so badly damaged, they looked interesting)

Checkerboard Legacy (approx. 9½ miles away in Idaho). Touch for a list and map of all markers in Lolo.

Regarding Taking The Waters. When I stopped here I thought I would take a plunge in the springs themselves, not the pool, but when they told me that the temperature was 107ºF I thought better of it.

Also see . . . Lewis and Clark in Montana, a geologic perspective -- Montana Tech. "... Both captains had a good command of geographic terms and used most of them in there current meaning. Both also seen to have had some concept of geologic time because they occasionally used the phase "in some former age" when referring to some river changes and geographic features." (Submitted on October 26, 2026, by Barry Swackhamer of Brentwood, California.)

Credits. This page was last revised on October 26, 2026. It was originally submitted on October 26, 2026, by Barry Swackhamer of Brentwood, California. This page has been viewed 7 times since then. Photos: 1, 2, 3, 4. submitted on October 26, 2026, by Barry Swackhamer of Brentwood, California.