Redside Rapids is a Class IV rapid on the Middle Fork Salmon River in Lemhi County, Idaho, about 82 miles down the Middle Fork's wilderness float from Boundary Creek. Lines through the rapid change with the flow.
The falls
Redside lies in the Impassable Canyon, the last stretch of the Middle Fork, named for its lack of any land route. Much of the trip's whitewater comes here, with Redside, Weber and Rubber among the rapids. The rapid features a short, steep drop between large boulders as the river bends right, rated Class III to IV. The rapid sits at about 3,302 feet, in the granite canyon country of the Idaho Batholith.
Getting there
Redside is reached by boat on the 100-mile trip from Boundary Creek to Cache Bar. A permit from Salmon-Challis National Forest is required year-round, and launches from May 28 to September 3 are allocated by lottery on Recreation.gov. Fees are $4 per person per day, or a Salmon Rivers Season Pass, plus a $6 reservation fee. From August 8 to September 15 each permit is limited to 12 watercraft to protect spawning salmon.
When to go
Flow is measured at the Middle Fork Lodge gauge, where the run spans 700 to 10,000 cfs, though 700 to 1,000 cfs may be too low for rafts, and up to 12,000 cfs. The line through Redside changes with the water level.
On site
Redside Camp, a small camp on a high bench with scattered timber, sits on river left just above the rapid at the mouth of a small creek. Scouting is done from the left bank here, avoiding the main hole and pulling left. A boater's July 2022 trip report on American Whitewater called Redside the hardest rapid of the run, found the left line easiest at that level, and watched groups on the center and far-right lines nearly flip.
Nearby
Porcupine Rapids is about 1.6 miles away, Cliffside Rapids about 5.3 miles, Ouzel Rapids about 6.4 miles and Haystack Rapids about 12.3 miles. Salmon is the nearest town, about 40.7 miles away.
Distances are straight-line.