Ryan Mountain Trail                                                   

See a variety of Proterozoic gneissic rocks intruded by granites

Map Keys View 7.5' and Indian Cove 7.5'

Trail Length 3 miles, ~2 hours

Elevation Change +1000 feet

Difficulty moderate

Directions Trailhead on the south side of Park Boulevard, west of Sheep Pass.

Description The trail begins in the Palms biotite granite, typical of Mesozoic granites in the central province of the Park. These granites form the boulder-strewn floors of Queen Valley and Paradise Valley. The trail climbs quickly southward and westward up into the Lost Horse Mountains. As you climb, notice that the granite soon gives way to gneiss. Although both the granite and the gneiss are tan in color and composed of the same minerals, the gneiss can be recognized by its relatively finer grain size and prominent layering. This gneiss is Proterozoic in age, much older than the Mesozoic Palms granite that intruded it. As the trail continues to climb, notice the abrupt transition into much darker, mica-rich gneisses. These darker-colored gneisses probably formed from metamorphism of still more ancient rocks formed from metamorphism of clay-rich sediments deposited on the floor of an ancient sea. As you walk, look to the south across the cove and see the contact where the Palms granite intrudes the same dark, mica-rich gneiss on which you are now standing. The trail climbs up onto the ridgeline of Ryan Mountain, the backbone of the Lost Horse Mountains. These mountains are composed of gneisses that are comparatively resistant to erosion, and so stand high above the granites on the valley floors to the east and west of the trail. You are rewarded with particularly good views of the surrounding granite-floored valleys from the summit of Ryan Mountain. Return to the trailhead the same way you came.

Touch an image to learn more about rocks and geology along this trail.