Hidden Falls is a 40-foot waterfall on Mill B North Fork in Big Cottonwood Canyon, Salt Lake County, Utah, reached by a short walk from the S-curve parking area.
The falls
Hidden Falls drops about 40 feet; a separate hiking site instead puts the visible fall closer to 25 feet, without a stated method.
Getting there
The route starts at the S-curve parking area about 4.4 miles up Big Cottonwood Canyon Road and crosses the road. From there it is a short, easy walk on dirt and rock; one guide gives 0.25 mile round trip with 53 feet of gain, while another gives 0.2 mile with 72 feet, its own text inconsistently citing 0.1 to 0.15 mile. Hidden Falls also appears among the trail destinations from the Mill B North Trailhead, where a listed 3,000 feet of elevation gain covers a longer mountain route beyond the waterfall, not the short walk to the falls themselves.
Since June 1, 2026, a parking fee has applied at the Mill B/S-curve lot: $10 per vehicle for three days, $20 for seven days, or $60 for an annual forest pass, with other interagency passes accepted; roadside spaces inside the posted fee boundary need a pass too.
When to go
Snowmelt in April and early May brings the fullest flow; hiking is generally feasible from March through early November. Winter brings ice, and late-summer flow drops.
On site
Salt Lake City watershed rules ban dogs and other domestic animals, swimming and wading in the protected waters of Big Cottonwood Canyon, so neither is allowed at the falls. The creekside approach can flood; snowmelt flooding was documented in May 2024, with the falls then viewed only from downstream. A fenced abandoned mine sits beside the approach, and visitors are told not to enter it.
Nearby
Lake Lillian Falls and Lake Blanche Falls, both on Mill B South Fork, are about 2.5 miles away. Heughs Canyon Falls is about 3.3 miles, and Doughnut Falls about 3.6 miles.
Distances are straight-line.