Knox - Swimming Hole near Cascade, Idaho
Cascade,Idaho
44.6649, -115.6973
19.8 miles NE of Cascade, Idaho
GPS: 44°39'53.6"N 115°41'50.3"W
Maps | Directions
State: Idaho

Swim

Knox is a wide, pool-filled stretch of the South Fork of the Salmon River near Warm Lake, east of Cascade, Idaho, in the Boise National Forest, prized for its sandy-bottomed pools and grassy banks that make it a fine spot for a swim and a streamside picnic. It sits near Knox Ranch, a historic mining settlement in the mountains above Cascade, in a quiet corner of central Idaho's high country where the South Fork runs clear and cold through a forest of towering old-growth ponderosa pine.

To reach it, drive south from McCall or north from the town of Cascade and turn east onto the Warm Lake Road, Forest Road 22, which climbs over the divide toward Warm Lake. Just before the lake, turn north onto a single-lane paved road that follows the South Fork of the Salmon River upstream, and park right away. From the pullout, walk up and over a low embankment on the side away from the river, cross the wood fence around the old Knox Ranch meadow, and drop down the hill to the water, where the current spreads into a series of calm, clear pools with sandy bottoms and grassy places to spread out a blanket.

The setting is classic central-Idaho backcountry. The South Fork is one of the state's great rivers, famous both for its fishing, with Chinook salmon, steelhead and smallmouth bass, and as a remote, exceptionally scenic multi-day whitewater run further downstream. The surrounding forest teems with wildlife, from deer, elk and bears to eagles, osprey and otters, and summer brings wildflowers and butterflies to the meadows.

The whole Warm Lake area is a popular summer escape, with Warm Lake itself, its lodges, and the Billy Rice day-use swim beach on the north shore only a short drive away, plus campgrounds, boating and miles of trails. The water at Knox is mountain-cold and the season is short, roughly July into September once the high roads open, and it is an undeveloped spot with no facilities, so come prepared. Peaceful, scenic and well off the beaten path, Knox rewards the drive for anyone after a quiet river swim in the Idaho pines.

Updated August 13, 2026

More Information

11 Fishing Holes in Southwest Idaho - Southwest Idaho Travel Association

The region is home to thousands of miles of reservoirs, rivers and lakes — and it’s one of the only places this far inland where you can catch steelhead trout and salmon.

https://www.visitsouthwestidaho.org/11-fishing-holes-in-southwest-idaho/

Boise National Forest : Recreation Site - South Fork Salmon River Campground

The South Fork Salmon River Campground hosts 11 campsites situated in a scenic forest of towering, old-growth ponderosa pine, which provides partial shade in the campground.Warm Lake is just a short distance away from the campground and visitors enjoy all the recreation opportunities that the lake has to offer in the day, while staying in a quiet setting for evening relaxation.Chipmunk Creek runs alongside the campground. Summer wildflowers and butterflies are abundant. There are lots of picnic and hiking opportunities. You may get a glimpse of variety of wildlife including bears, deer, elk, fox, grouse, eagles, osprey, grosbeaks, whooping cranes and otters, that live in the area.Recreation:Just a short drive from the campground, is Warm Lake offering great fishing opportunities for cutthroat, rainbow, lake and bull trout. Boating, canoeing and swimming are also popular activities.Billy Rice Swim Beach is available at Warm Lake Lodge on the north side of the lake. The area offers a day-use site for picnicking and swimming. There is a boat ramp is located at nearby Shoreline Campground.The surrounding area offers great hiking, mountain biking, horseback and off-road vehicle riding, and hunting. The WeWuKiye (Wa Wu Kia) Trail No. 252 was recently built and can be accessed at Shoreline Campground. It is popular for hiking and mountain biking.For off-road vehicle enthusiasts, Telephone Ridge Trail No. 112 offers 20 miles of trails for all riding levels, with staging areas at Shoreline Campground.In September, you may want to visit the South Fork Salmon River fish viewing site. The bridge-walkway enables you to see to see chinook salmon that have traveled 700 miles from the Pacific Ocean to spawn.

https://www.fs.usda.gov/r04/boise/recreation/south-fork-salmon-river-campground

South Fork Salmon River Camping | Cascade, Idaho

South Fork Salmon River: 2 Reviews, 5 Photos, $15 per night. ā€œSmall quiet campground, it is right off the road but it wasn’t busy for us. Campsites righ…

https://thedyrt.com/camping/idaho/idaho-south-fork-salmon-river-campground

South Fork Salmon River Idaho Fly Fishing, Camping, Boating

Your Complete Travel Guide For McCall Idaho. Check Out: Lakes Rivers Falls > South Fork Salmon River

https://www.allmccall.com/lakes_rivers_falls/south_fork_salmon_river.php
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  1. Plan Ahead and Prepare
  2. Travel & camp on durable surfaces
  3. Dispose of waste properly
  4. Leave what you find
  5. Minimize campfire impacts
  6. Respect wildlife
  7. Be considerate of other visitors

Directions

From Cascade, Idaho

  1. Head northwest toward W Pine St (289 ft)
  2. Turn left onto W Pine St (151 ft)
  3. Turn right onto ID-55 N/N Main St
    Continue to follow ID-55 N
    (0.9 mi)
  4. Turn right onto NF-22/Warm Lake Rd (16.4 mi)
  5. Keep left (0.9 mi)
  6. Continue onto NF-22/Warm Lake Rd (6.2 mi)
  7. Turn left onto Forest Rd 474CA (0.2 mi)
or

From McCall, go south on ID-55 to Cascade. Turn east (left) on Warm Lake Road (FR 22). Just before you reach Warm Lake, turn north (left) on a single-lane paved road along the South Fork of the Salmon River and park right away. There is an embankment above the road on the side away from the river; walk up this hill and cross a wood fence around the meadow at Knox Ranch, a historic mining settlement. Walk south, down a hill away from the meadow, to a wide stream full of pools with sandy bottoms and grassy picnic spots.

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The South Fork of the Salmon River near Warm Lake courtesy of Northwest Rafting Company(BY 2.0) The South Fork of the Salmon River near Warm Lake courtesy of Northwest Rafting Company↗ (BY 2.0)
Scenery along the South Fork Salmon River courtesy of Northwest Rafting Company(BY 2.0) Scenery along the South Fork Salmon River courtesy of Northwest Rafting Company↗ (BY 2.0)

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