Near Simms in Cascade County, Montana — The American West (Mountains)
Bird Tail Rock
Photographed by Barry Swackhamer, August 20, 2019
1. Bird Tail Rock Marker
Inscription.
Bird Tail Rock to the southeast was one of the most prominent landmarks along the Benton Road between Fort Benton and Helena. An igneous intrusion about 55 million years old, it acquired its name because it resembled a "bird's tail" erect and spread out in a fan-shape. "Following an old Indian Trail, Lieutenant John Mullan built a road past this extraordinary geological feature in July 1960. The rock was located on a steep divide about midway between the Sun River and Dearborn River crossings. At first, Mullan was not sure wagons could be able to traverse the rugged terrain here. But after pulling a two-wheel cart over the divide in 1859, his assistant, P.M. Engel, determined the route "practicable for wagons in its present state." With the discovery of gold in southwestern Montana in the early 1860s, the road now known as the Benton Road, was heavily used by freighters and stagecoaches traveling between Fort Benton and Helena. In 1881, a traveler on the road reported that Bird Tail Divide "was more or less dangerous... and perhaps the lost trying piece of stage road in northwestern Montana during the winter season, as the snow-drifts frequently obliterated all traces of (it) for miles."
Bird Tail Rock to the southeast was one of the most prominent landmarks along the Benton Road between Fort Benton and Helena. An igneous intrusion about 55 million years old, it acquired its name because it resembled a "bird's tail" erect and spread out in a fan-shape. "Following an old Indian Trail, Lieutenant John Mullan built a road past this extraordinary geological feature in July 1960. The rock was located on a steep divide about midway between the Sun River and Dearborn River crossings. At first, Mullan was not sure wagons could be able to traverse the rugged terrain here. But after pulling a two-wheel cart over the divide in 1859, his assistant, P.M. Engel, determined the route "practicable for wagons in its present state." With the discovery of gold in southwestern Montana in the early 1860s, the road now known as the Benton Road, was heavily used by freighters and stagecoaches traveling between Fort Benton and Helena. In 1881, a traveler on the road reported that Bird Tail Divide "was more or less dangerous... and perhaps the lost trying piece of stage road in northwestern Montana during the winter season, as
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the snow-drifts frequently obliterated all traces of (it) for miles."
Location. 47° 20.13′ N, 112° 4.613′ W. Marker is near Simms, Montana, in Cascade County. It is on State Highway 200 at milepost 114 near U.S. 287, on the right when traveling west. Touch for map. Marker is in this post office area: Simms MT 59477, 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 Ruperts Land and also the Louisiana Purchase.
Credits. This page was last revised on February 14, 2026. It was originally submitted on January 1, 2020, by Barry Swackhamer of Brentwood, California. This page has been viewed 3,341 times since then and 196 times this year. Photos:1, 2. submitted on January 1, 2020, by Barry Swackhamer of Brentwood, California.
