Lamar River Trail

The Lamar River Trail is a remote out-and-back from Soda Butte / Lamar River Trailhead (3K1) to Cold Creek: 33 miles round trip. It follows the east side of the Lamar River through the Lamar Valley. Budget about 18 hours on foot; that is a planning estimate, since the park gives no time. This is an exceptionally long day unless you have the fitness and daylight for it. If you want a shorter hike, Cache Creek is a common turnaround at 7.2–7.3 miles round trip, a shorter portion of this same trail. Overnight backcountry camping requires a permit.

The walk starts across a bridge over Soda Butte Creek, with open views toward the grasslands and low mountains and, in the other direction, Abiathar and Barronette peaks. It climbs above the creek and a bluff, then crosses sagebrush to the Stock Trail and Specimen Ridge junctions. After the Specimen Ridge junction, the route rises above Lamar Valley toward a pass, with views toward Mirror Plateau and a pale geothermal hillside. The narrow dirt track through grass makes the Cache Creek stretch feel gentler than its distance suggests, but it still gains about 837 feet round trip.

The common day-hike turn is at the creek bank about 3.6–3.8 miles from the trailhead. Continuing the full route requires a creek crossing beyond that junction, then follows the Lamar River corridor much farther to Cold Creek. Park streams can rise during the day and crossings can be hazardous, so check current conditions with the park before continuing. The full route is mapped as one outbound corridor; the 33 miles includes the return along the same path.

The park notes that hikers have a chance to see many of Yellowstone’s large mammals in this part of Lamar Valley; bison have been seen on the valley floor, but sightings are not guaranteed. Grizzly bears frequent the area. The park recommends hiking in groups of three or more, keeping bear spray accessible, and not hiking after dark. Pets are not allowed on the trail.