Necklace Valley / Foss Lakes Loop
~3 days · 23.5 mi · hard · Multi-day trek
Quick facts
What the Necklace Valley / Foss Lakes Loop is known for
This rugged loop in Washington's Alpine Lakes Wilderness links the West Fork Foss lakes with the chain of small alpine lakes in Necklace Valley. Published figures run about 26 miles with roughly 9,000 ft of gain, including a brushy off-trail crossing between the two valleys, so it suits experienced navigators. Most parties take 3 days.
Elevation profile
Elevation ranges from 5,394 ft to 19,062 ft over 23.5 mi. Measured from OSM geometry (approximate).
- Uphill 10.7 mi · 46%
- Downhill 12.0 mi · 51%
- Flat 0.8 mi · 3%
Ridgefold breaks every route into uphill, downhill, and flat — see the full per-day breakdown in the app.
Frequently asked questions
How many days does the Necklace Valley / Foss Lakes Loop take?
Most backpackers hike the Necklace Valley / Foss Lakes Loop in about 3 days (2 nights out) over its 23.5 miles, though pace varies with fitness and conditions.
How much elevation gain is on the Necklace Valley / Foss Lakes Loop?
The Necklace Valley / Foss Lakes Loop climbs roughly 7,759 ft total — about 330 ft per mile, topping out near 5,814 ft.
Related trails
Sources & attribution
Route geometry and stats derived from OpenStreetMap (© OpenStreetMap contributors, ODbL) — source relation. Stats are approximate and may differ from official surveys; permit rules and conditions change — verify with the managing authority before your trip. Last reviewed July 2026.