Fig. 1. Sierra Nevada fish sample locations and the general range of our main study area (indicated by shaded area) for high-altitude rainbow trout sampling, and an expanded map showing three sites in the central Sierra Nevada area where trout samples were collected (see arrows). Bold lines indicate high mountain divides between 3663 and 4273 m elevation. Site A: Blue Lake at 37°8'N, 118°37'30° W directly east of Mt. Mendel (4179 m) and Mt. Darwin (4240 m), a 4-h hike from Lake Sabrina. Site B: Rae Lake, Sixty Lakes Basin at 36°57'N, 188°23'W, directly east of Mt. Gardiner (3959 m) and west of Black Mountain (3970 m), a 2-d hike from Onion Valley (2803 m) through Kearsarge (3526 m) and Glenn Pass (3656 m). Site C: Pear Lake at 36°37'N, 118°40'W, directly west of Elizabeth Pass (3611 m), 3 h from Wolverton.