Trilobite Lake Trail

The trailhead for the Trilobite Lake Trail is found at the rear of the Winter Creek Patrol Cabin, 5.8 miles from the trailhead for the Mount Holmes-Winter Creek Trail. The seldom used trail leads steeply up 840 feet and drops into a glacial depression housing a beautiful lake. From the patrol cabin, the trail enters the heavily burned forest and climbs modestly. The trail may be difficult to find in places, so watch closely for trail markers and signs of the trail on the ground. At the .3-mile mark, the trail crosses a small unnamed creek. It continues to the .7-mile mark and crosses another small creek. At the 1-mile mark, the trail begins to climb more steeply and at 1.9 miles tops out the 840-foot climb. From there it drops 170 feet down to Trilobite Lake. Eleven-acre, Trilobite Lake has a maximum depth of 43 feet and sports a population of brook trout. The lake sits at the base of a geologic "cirque," a semicircular hollow or amphitheater eroded in the mountain by glaciers. From the lake, there are good views of the top of Mount Holmes. There are several other smaller lakes deeper in the cirque. The moisture from the lakes and the shelter of the mountain prevented the forest around the lakes from burning in 1988. A "trilobite" is an extinct Paleozoic marine arthropods with segments of its body divided by furrows. They are popular (and relatively inexpensive) fossils, found in many rock shops. The Gallatin Range is the only non-volcanic, sedimentary rock mountain range in the park. The rocks here formed from the accumulation and consolidation of sea floor sediments. Geologists William Holmes (for whom Mount Holmes is named) found trilobite fossils in the mountain ridge to the south, and named it Trilobite Point. Thanks to guidebook author, Tom Carter, for sharing this trail description. To learn more about visiting Yellowstone, check out his book, Day Hiking Yellowstone.