Near Great Falls in Cascade County, Montana — The American West (Mountains)

White Bear Islands

Ever-changing Riverbanks

Photographed by Barry Swackhamer, June 23, 2026

1. White Bear Islands Marker

Caption: (middle left) Extensive research had produced this areal view, using a recent photo to compare today's landscape with the one from 1805. Bob Bergantino, widely recognized as the world's leading expert on locating the expedition's travel routes and campsites, used Clark's map and narrative to determine the precise location of the Upper Portage Camp and extent of the White Bear Islands. This map also illustrates Bergantino's conclusions about the route followed by the portage crew in its final approach t the campsite.

Inscription. At the time of Lewis and Clark, with thousands of bison crossing the in this area, the riverbanks and islands were a predator's feast ground. Many of the bison perished in the rushing waters. Their rotting carcasses attracted so many wolves and grizzlies that the expedition's hunting parties often left a man behind to guard meat when it couldn't be carried back in a single trip. Grizzlies, which can appear silvery white in certain kinds of light, inspired the Corps of Discovery's name for its camp and for the three islands that existed at the time.
Years of constant geologic action-along with the effects of human development-have narrowed the Missouri River here, making it difficult to picture the location of both the Upper Portage Camp and Lewis and Clark's three "White Bear Islands." Upstream dams change seasonal water flows and increased the quantity of natural sedimentation. Slowly, sediments deposited here have been linking the islands to the riverbank. As you look to the south, use the aerial photo-map below to get a better idea of what this area was like when Lewis and Clark camped here in 1805.

"the White bear have become so troublesome to us that I do not think it prudent to send one man alone on an errand of any kind, particularly where he has to pass through the brush we have seen two of them on the large Island opposite to us today but are so much engaged that we could not spare the time to hunt. they come close arround our camp every night but have never yet ventured to attack us and our dog gives us timely notice of their visits.... I have made the men sleep with their arms by them as usual for fear of accedents."

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Meriwether Lewis, June 28, 1805

Erected by Montana State University, Bozeman; U.S. Dept. of the Interior; Montana Stock Growers Association.

Topics and series. This historical marker is listed in these topic lists: Animals • Exploration • Natural Features. In addition, it is included in the Lewis & Clark Expedition series list.

Location. 47° 27.859′ N, 111° 17.641′ W. Marker is near Great Falls, Montana, in Cascade County. It can be reached from 40th Avenue South near 13th Street South, on the left when traveling west. Touch for map. Marker is at or near this postal address: 700 40th Avenue South, Great Falls MT 59405, United States of America. Touch for directions.

Regionally, this marker is in andspecifically entral Montana in Russell Country. 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

Photographed by Barry Swackhamer, June 23, 2026

2. White Bear Islands Marker

least 8 other markers are within 2 miles of this marker, measured as the crow flies: Upper Portage Camp (within shouting distance of this marker); Lewis's Grand Experiment (within shouting distance of this marker); The Portage Route (within shouting distance of this marker); Welcome to the Upper Portage Overlook (within shouting distance of this marker); Commissary of the Plains (approx. 2 miles away); The Falls: Obstacle or Opportunity (approx. 2 miles away); The Portage Around the Falls (approx. 2 miles away); Explorers at the Portage (approx. 2 miles away). Touch for a list and map of all markers in Great Falls.

Credits. This page was last revised on October 18, 2026. It was originally submitted on October 18, 2026, by Barry Swackhamer of Brentwood, California. This page has been viewed 8 times since then. Photos: 1, 2. submitted on October 18, 2026, by Barry Swackhamer of Brentwood, California.