The Merced has Rainbow, Brook, and Brown Trout as well as Largemouth, Smallmouth and Stripped Bass within the lower reaches to Lake McClure.
Some of the best water on the Merced for trout is where the South Fork meets the main river and continuing upstream to about the Park Boundary. The river is stocked from the South Fork to Foresta Bridge. From the South Fork confluence to
Yosemite Valley the river has more pocket water and riffles and becomes more suitable for fly fishing. Indian Flat Campground gets a heavy fishing
pressure due to trout planting. Upstream from Foresta Bridge to the Yosemite NP Border, it is open year-round. It's catch and release only for Rainbows and a limit of 5 Brown Trout daily, 10 in possession with single barbless hooks and artificials. This is a Wild Trout area with Browns and Rainbows in the 8-12 inch class.Most of this section is pocket water, riffles and rapids,
with few pools. A salmonfly hatch begins within this area in April but the high water makes fishing difficult. Wading is possible starting in mid-June
and nymphing can be your best method as the water warms up and the fish stay low. Most of this area is a rafting area which ceases around the end of June. Before the snow melt, the fishing is good in February and March, then try again starting in July after the snowmelt. Below the Foresta Bridge the season is also year-round, with a limit of 5 trout from the last Saturday of April to November 15th. The rest of the period is a 2 trout limit. Below the South Fork confluence there is a good population of smallmouth bass. These smallies will hit the leech and bugger patterns.
Within the Park, the season for the Merced is last Saturday in April to November 15th with catch and release only for Rainbows and a limit of 5 Brown Trout with single barbless hooks and artificials. The best areas are the Gorge, just below the valley. This is pocket water with Rainbows and Browns, 8-12 inches and a few up to 14 inches. Due to snowmelt, it is not fishable until July when the Caddis and Mayfly hatches come off. Flow measurements are taken at Pohono Bridge within the Park. Safe wading flows are usually less than 200 cfs.
Major hatches are the PMD starting in June and extending until the end of September. Caddis are also prevalent. During late February to March BWO, Baetis, and Golden Stones are evident. Stoneflies will emerge during April and May. June is a good time for hopper patterns. Ants work throughout the summer. The river gets a lot of river rafting activity during the spring and early summer months. Wading can also be very risky during the Spring run-off period.
Most use a 5-6 weight rod with a 9 foot 3X leader and 4-8 feet of 3X-5X tippet. The best dry fly condition is during the late fall using size 16-18 flies. During mid-spring, deep nymphing is your best bet. You must weight the line about 4 feet above a weighted nymph.
Merced River from the Happy Isles footbridge downstream to the western boundary of Yosemite National Park at El Portal.:
Last Saturday in Apr. through Nov. 15. Only artificial lures with barbless hooks may be used. 0 Rainbow trout, 5 Brown trout per day. 10 brown trout in possession.
Merced River from the western boundary of Yosemite Valley National Park at El Portal downstream to Foresta bridge.:
All year. Only artificial lures with barbless hooks may be used.0 Rainbow trout, 5 Brown trout per day. 10 brown trout in possession.
Merced River from Foresta bridge downstream to Lake McClure.:
Last Saturday in Apr. through Nov. 15. 5 trout per day. 10 trout in possession.
Nov. 16 through the Friday preceding the last Saturday in Apr. 2 trout.
Other Rivers and Streams:
Last Saturday in Apr. through Nov. 15. No restrictions. 5 trout per day. 10 trout in possession.
Lakes within this area:
Open all year. No restrictions. 5 trout per day. 10 trout in possession.