Washington · Rock climbing · Skykomish

Great Slab

Great Slab in Washington has 7 bouldering routes with crash pads.

7 routes
V0 – V3
Bouldering

Is Great Slab open right now?

Closure in the area

There's a closure order in Mt. Baker-Snoqualmie National Forest. It doesn't name Great Slab, so check the source for the area it covers (2 listed).

As of · Source: USFS · Mt. Baker-Snoqualmie National Forest. Agencies don't list every closure — check before you go.

Best time to visit Great Slab

Best months: July–September. Best months have typical highs of 55–85 °F, lows of 30 °F or warmer (32 °F where the station doesn't record snow), at most one snowy day and no more than 12 wet days.

  1. Jan

    32° / 25°

    20 wet

  2. Feb

    35° / 26°

    17 wet

  3. Mar

    40° / 29°

    20 wet

  4. Apr

    46° / 33°

    19 wet

  5. May

    53° / 38°

    17 wet

  6. Jun

    60° / 43°

    14 wet

  7. Jul

    68° / 50°

    8 wet

  8. Aug

    69° / 51°

    7 wet

  9. Sep

    63° / 47°

    10 wet

  10. Oct

    49° / 38°

    16 wet

  11. Nov

    38° / 30°

    19 wet

  12. Dec

    32° / 24°

    20 wet

Typical high / low (°F) and days with rain or snow, 1991–2020. Measured at Stampede Pass, WA, 34.8 mi away at 3,959 ft. This station doesn't record snowfall. Source: NOAA NCEI U.S. Climate Normals 1991–2020.

Closures we've recorded since August 2026

  • Campfire Ban in Effect Forest-wide

    Mt. Baker-Snoqualmie National Forest · Order dated July 21, 2026; seen Aug 23, 2026 → lifted Sep 15, 2026 · Forest Service

Great Slab is a bouldering area in the Henry M. Jackson Wilderness, within the Skykomish Ranger District of Mt. Baker-Snoqualmie National Forest in Washington. The Forest Service manages the land, and the area sits inside designated wilderness. The climbing here is all bouldering, with seven routes spread across the slab. The easiest are Great Slab Center and Great Slab Left, both rated V0, and the hardest are Gravy and Poutine, rated V3. The routes are close together, with Whiteface Cluster and Steam Roller Cave each about 0.1 mile away. Summer is the most comfortable time to visit. Typical averages from the Stampede Pass weather station, about 35 miles away, show July and August highs near 68 to 69°F with only seven or eight wet days a month, while winter brings highs around freezing and rain on most days. The Iron Goat Trail is about 1.4 miles away, and the Grace Lakes Cat Track is about 1.7 miles away. For an overnight stay, Evergreen Mountain Lookout is about 8 miles off.

Routes (7)