Big Heart Lake, West Fork Foss Trailhead, Seattle - Alpine Lakes Wilderness - Snoqualmie Pass - Central Cascades, Washington

Big Heart Lake - 16.0 miles

West Fork Foss Trailhead

Big Heart Lake

Big Heart Lake

Round-Trip Length: 16.0 miles
Start-End Elevation: 1,500' – 4,418' (4,701' max elevation)
Elevation Change: +2,918’ net elevation gain (+3,903' total roundtrip elevation gain)
Skill Level: Strenuous
Dogs Allowed: Yes
Bikes Allowed: No
Horses Allowed: No
Related Trails:

Big Heart Lake - 16.0 Miles Round-Trip

The West Fork Foss River Trail reaches deep into the highest concentration of lakes in the Alpine Lakes Wilderness between Highway 2 and I-90. Big Heart Lake is located 8.2 miles from the trailhead in a stunning cirque at the head of the valley. Visitors will enjoy varied terrain, several waterfalls, access to multiple lakes and great camping on the hike to Big Heart Lake:

Trail Map | Photo Gallery

The trail enters the Alpine Lakes Wilderness and joins the West Fork Foss at .4 miles. Views open to Shoestring Falls and the rocky ridge of Malachite Peak as it winds past debris from a 2006 flood to a new footbridge over the river (.98 miles : 1,675’).

Once across it rises gently in a captivating forest of ancient hemlock and cedar to Trout Lake (1.85 miles : 1,920’). The day use area here includes a natural swimming beach, established campsites and privy.

The trail arcs west past Trout Lake along Copper Creek to Upper Copper Falls (2.4 miles: 2,264’), then begins a 2 mile climb on switchbacks toward the bench holding Malachite and Copper Lakes. It gains 1500' between Trout and Copper Lake on this long, methodical climb.

The trail switchbacks along the creek through open areas of fireweed and vine maple to Malachite Falls at the headwall below Malachite and Copper lakes. It crosses under some granite crags and fords a stream at 4.0 miles (3,305’).

Travel moderates after crossing a creek at 4.2 miles and passes through yellow cedar and mountain hemlock to the Lake Malachite junction (4.75 miles : 3.751’). A short, steep spur breaks .2 miles west to Lake Malachite (3,990’).

The main trail keeps straight across an outlet creek on flat stones to the north end of Copper Lake (5.1 miles: 3.780’). It undulates and winds above Copper Lake's east shore with great views of the cirque, bending SE past the far end along a creek up to Little Heart Lake (6.47 miles : 4,026’).

While campsites are difficult to find here, there a few good ones lower on the climb between Copper and Little Heart.

Switchbacks resume at 6.6 miles up a divisive ridge between Little Heart Lake and Big Heart Lake. The trail climbs 700’ to the ridgetop (6.9 miles), and eases briefly with views over a small pond before continuing up and around the conical ridge.

It rounds the far side of the ridge with views down West Fork Valley to Trout Lake and Glacier Peak (7.5 miles : 4,700’). Here it drops 300' through intervals of talus and old growth timber to Big Heart Lake (8.0 miles : 4.418’). Established campsites and a privy can be found on the south side of the log-jammed outlet creek, with more campsites north of the creek.

For an adventurous extension, continue along Big Heart Lake to gain a minor ridge separating it from Angeline Lake to the SE.  From here a rugged, unmaintained track can be followed into the East Fork Foss lakes basin – a traverse dubbed the Alpine Lakes High Route by Fred Beckey.

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Interactive GPS Topo Map

Key GPS Coordinates - DATUM WGS84

  • N47 38.087 W121 18.234 — 0.0 miles: West Fork Trailhead
  • N47 37.857 W121 18.529 — 0.4 miles: Trail joins West Fork Foss
  • N47 37.613 W121 18.665 — 0.8 miles: Trail winds past washout debris
  • N47 37.576 W121 18.790 — 1.0 miles: Bridge over West Fork - 1,675'
  • N47 37.567 W121 18.864 — 1.1 miles: Enter Old Growth Grove
  • N47 37.340 W121 18.884 — 1.55 miles: Trail continues gradual ascent
  • N47 37.118 W121 18.850 — 1.85 miles: Trout Lake - 1,920'
  • N47 36.745 W121 19.055 — 2.4 miles: Upper Copper Falls - 2,264'
  • N47 36.740 W121 19.277 — 3.0 miles: Steep ascent continues via switchbacks
  • N47 36.812 W121 19.464 — 3.5 miles: Ascent continues via switchbacks
  • N47 36.849 W121 19.745 — 4.0 miles: Ford small stream - 3,305'
  • N47 36.792 W121 19.836 — 4.2 miles: Log bridge across stream
  • N47 36.645 W121 19.919 — 4.5 miles: Trail continues moderate ascent
  • N47 36.630 W121 19.983 — 4.75 miles: Spur to Malachite Lake - 3,990'
  • N47 36.456 W121 19.752 — 5.1 miles: Copper Lake - 3,780'
  • N47 35.958 W121 19.843 — 6.0 miles: Trail hugs east side of Copper Lake
  • N47 35.608 W121 19.720 — 6.4 miles: Moderate ascent to Little Heart Lake
  • N47 35.756 W121 19.472 — 6.9 miles: Brief respite from steep ascent
  • N47 35.520 W121 19.156 — 7.5 miles: Top of ridge - Apex of hike - 4,701'
  • N47 35.113 W121 19.201 — 8.0 miles: Big Heart Lake - 4,418'

Worth Noting

  • Trout Lake is an ideal day or overnight destination for anglers, groups and families.

Camping and Backpacking Information

  • Camp only at established campsites when within 1/2-mile of the following locations: Big Heart Lake, Copper Lake, Lake Dorothy, Little Heart Lake, Malachite Lake, Surprise Lake, and Trout Lake.

  • An overnight Wilderness permit must be filled out at the TH and carried to camp at Copper or Big Heart Lakes.

  • Campfires are prohibited at all lakes accessed by West Fork Foss Trail.

  • Group size is limited to 12.

  • Pack out all trash | Practice leave no trace ethics.

Fishing Information

  • Fishing is allowed with a valid WA state fishing license.

  • Contact the Washington Department of Fish and Wildlife for more information.


Email: [email protected]
Sport/Commercial Licenses: 360.902.2434
Disability Licenses: 360.902.2460

Rules and Regulations

  • A Northwest Forest Pass or $5 fee is required at this trailhead.
  • A free day use or overnight Wilderness Permit must be filled out at the TH and carried for the duration of your trip in the Alpine Lakes Wilderness.
  • Dogs must be leashed at all times in the Alpine Lakes Wilderness.
  • Horses are not permitted on this trail.

Directions to Trailhead

The West Fork Trailhead is located 6.6 miles from the Foss River Road turnoff on Highway 2 east of the town of Skykomish.

From Highway 2 (Stevens Pass Highway), turn south on Foss River Road, 1.9 miles east of Skykomish. Continue straight on 68 where the pavement ends at 1.2 miles. At a Y-junction at 3.5 miles stay right, passing another trailhead parking lot at 4.2 miles. Just before a bridge, at 4.7 miles, turn left on 6835 (sign is easy to miss) and continue 1.9 miles to West Fork parking lot and trailhead.

The parking lot holds 30 cars and has bathrooms. 

Contact Information

Mt Baker-Snoqualmie National Forest | Skykomish Ranger District
74920 NE Stevens Pass Hwy | PO Box 305
Skykomish, WA 98288

Reference Trail #1064

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