Valley Geology & Basin Depth
Hidden deep within the Stone Valley Reserve, Emerald Glen Plunge Pool is fed by high-alpine snowmelt streams that converge into a narrow volcanic basalt chute. The water shoots outward with force before plummeting 45 feet down into an icy, 28-foot-deep natural plunge basin.
The distinctive deep green turquoise coloration of the basin stems from fine rock dust suspended in the mineral-dense water, combined with light reflecting off the dark basalt bedrock below.
📍 Technical GPS & Trail Breakdown
Trailhead Coordinates: 41°28'11.8"N 122°08'44.1"W
Elevation Gain: 820 feet (steeep switchbacks)
Trail Surface: Loose shale, river rock boulder scrambles
Safety Note: Strong underwater currents near the waterfall base. Swimming is only advised during late summer low-flow periods.
Trekking the Stone Valley Ridge
Hikers should begin at the South Rim trailhead. The first 2 miles climb steadily through pine timber before descending into the steep basalt canyon along a series of timber staircases. Gloves and sturdy ankle-support boots are highly recommended due to loose scree sections.
Wilderness Photography Tips
To capture the powerful spray and motion of Emerald Glen, ultra-wide wide-angle lenses (14-24mm) work best from the rocky shoreline. Pack ultra-absorbent microfiber cloths; mist buildup on front lens elements is constant within 50 feet of the plunge pool landing zone.