Merced River

The Merced is the river you already know from the postcards — the one that carves through Yosemite Valley under El Capitan and Half Dome, fed by Nevada and Vernal Falls at Happy Isles. As a fishery it lives in the shadow of the scenery and, honestly, in the shadow of the rafts: from June through August the Valley reach is a float-tube-and-inner-tube highway, and the fishing is a quieter, secondary use of the water. The fish are wild rainbows — native, catch-and-release only and barbless from Happy Isles down to Foresta Bridge — a scattering of browns, and the odd brook trout. Nobody comes here for size. Valley rainbows mostly run 8–12 inches, with browns to maybe 15–18 in the deeper gorge pools. People come because you can catch a wild trout on a dry fly with Half Dome over your shoulder.

Practically, this fishes like a classic Sierra freestone, which means it's all about the runoff calendar. Happy Isles peaks over 1,000 CFS on snowmelt in May and June; the Valley reach only becomes genuinely wadeable and worth fishing once it drops below roughly 250 CFS, which in a normal year is late June into July. The window then runs through the fall until the season closes November 15. It's a wading game — pocket water and riffles in the Valley, technical shy fish that feed heavily at night, and a much rockier, more dangerous canyon downstream in the Merced Gorge where high water is genuinely hazardous. Standard freestone tactics work: a Golden Stone or Little Yellow Stone dry-dropper, small attractor dries (Parachute Adams 14–18), and Pheasant Tail or Hare's Ear nymphs drifted through the pockets.

The warm-water problem is real and worth planning around. The Happy Isles gauge streams water temperature, and by mid-July the exposed Valley water was already reading about 62°F — it climbs fast on hot bluebird afternoons and pushes the fish onto a dawn-and-dusk schedule in the heat of summer. Access is the easy part: Highway 140 shadows the river from the Valley down through El Portal with endless turnouts, and Highway 41 gets you to the quieter South Fork near Wawona. The catch is Yosemite itself — peak-season entrance reservations, brutal Valley parking, and a fishery genuinely crowded with non-anglers. Manage expectations on fish size and you'll have a good day.