Guides/Overland routes/Washington
Overland route55 midifficulty: easy

Mountain Loop Highway

RegionWashingtonAgencyU.S. Forest ServiceLast verified—
Mountain Loop Highway — overland route near Granite Falls, Washington, Washington
Photo by Ron Clausen, CC BY-SA 4.0
Trail vitals6 facts
Length
55mi
Technical difficulty
Easy
Direction
Loop
Vehicle
Standard high-clearance vehicle. Two paved segments are passenger-car friendly; the 14-mile gravel middle section is single-lane and rough but passable in stock 4x4 or higher-clearance 2WD in dry conditions. Trailers and RVs not recommended on the gravel.
Best months
Jul, Aug, Sep, Oct
Cell coverage
Patchy near Granite Falls, Verlot, and Darrington. None on the gravel middle.
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The Mountain Loop Highway is a 55-mile National Forest Scenic Byway linking Granite Falls and Darrington across Mt. Baker-Snoqualmie National Forest. Pavement covers the western leg from Granite Falls past Verlot to Barlow Pass and the eastern leg from Darrington to the White Chuck River Road junction. Between them, a 14-mile single-lane gravel section drops over the divide and follows the Sauk River.

The loop dates to 1891 mining-era pack routes that loggers and the Civilian Conservation Corps later widened into a road. Federal designation as a National Forest Scenic Byway came in 1991. Snow closes the gravel middle from late fall into late spring most years; the paved ends stay open year-round but the loop only runs end-to-end after the Forest Service clears the higher stretches. Three wilderness areas (Boulder River, Henry M. Jackson, Glacier Peak) border the route.

Hazards

Read before you go

  • Seasonal closure. Snow closes the gravel middle most of the year. The paved ends stay open but become out-and-backs.
  • Single-lane gravel. Tight sections with limited turnouts. Drive defensively.
  • Washouts. Spring melt and storms reshape the gravel section every year.
  • Crowds. Summer weekends pack the Granite Falls end. Plan early.
  • Ice caves are dangerous. Stay outside.
  • No cell coverage on the gravel section.
  • Black bear country. Store food properly.

Location

55 mi · Overland route

Approx. location 48.086, -121.462

Trail facts

5 fields
AgencyU.S. Forest Service
Nearest townGranite Falls, Washington
Websitewww.fs.usda.gov/r06/mbs/recreation/mountain-loop-scenic-byway
ClosedNov, Dec, Jan, Feb, Mar, Apr
Approx. location48.086, -121.462

Getting there

Directions

Western entrance (Granite Falls). From I-5 at Marysville, take SR-528 east to Granite Falls, then continue east on the Mountain Loop Highway. The road is signed from town.

Eastern entrance (Darrington). From I-5 at Arlington, take SR-530 east 32 miles to Darrington. The Mountain Loop Highway leaves Darrington heading south, signed from the town.

Loop direction. Most drivers run it east-from-Granite Falls so the paved leg comes first, then the gravel descent to the Sauk River, then the easier paved exit to Darrington. The reverse works equally well.

Photos

2 photos

Photos · 2

Field notes

Getting Oriented

The loop sits in Snohomish County, an hour northeast of Seattle. The Granite Falls end leaves SR-92 east of town; the Darrington end leaves SR-530 (the Mountain Loop Highway is signed from town). The Verlot Public Service Center, a Forest Service ranger station roughly 11 miles east of Granite Falls, is the standard stop for permits and current conditions.

Trail Overview

Fifty-five miles, loop. The Granite Falls-to-Barlow Pass leg (about 30 miles) is fully paved and runs along the South Fork Stillaguamish River past the major hiking and ice-cave attractions. Barlow Pass is the high point at roughly 2,361 feet. The 14-mile gravel section between Barlow Pass and the White Chuck River Road follows the Sauk River north through deeper forest with no services and tighter sightlines. The Darrington end (about 11 miles) is paved again. The gravel section closes seasonally and is graded but rough; outside-corner washouts are common after spring melt.

Points of Interest

  • Verlot Public Service Center. USFS ranger station with maps, permits, and current condition info.
  • Big Four Ice Caves Trail. Popular short hike to ice caves at the base of Big Four Mountain. Caves are dangerous to enter.
  • Lake Twenty-Two Trailhead. Old-growth forest hike and lake basin.
  • Gold Basin Campground. USFS developed campground on the South Fork Stillaguamish.
  • Turlo and Verlot Campgrounds. Two more developed campgrounds near Verlot.
  • Big Four Picnic Area. Day-use area with views of Big Four Mountain.
  • Barlow Pass. High point of the loop, with the Monte Cristo townsite spur road and trailheads.
  • Bedal and Clear Creek Campgrounds. Forest Service campgrounds on the eastern, paved-near-Darrington stretch.
  • Boulder River, Henry M. Jackson, and Glacier Peak Wildernesses. All three border the loop with foot-only access trails.

Where to Camp

The loop has six developed Mt. Baker-Snoqualmie campgrounds: Turlo, Verlot, Gold Basin, Red Bridge, Coal Creek Group, and the Bedal / Clear Creek pair on the eastern end. Most reservable through Recreation.gov from late spring into early fall. Dispersed camping is permitted on national forest land away from developed sites with the standard 14-day limit. The major commercial bases are Granite Falls and Darrington, both with small grocery stores; full-service stops are Marysville (south) and Arlington (west).

Tips for a Safe and Enjoyable Trip

  • The gravel middle opens late, often not until late June or July. Check the Verlot Public Service Center (360-691-7791) before counting on the full loop.
  • A Northwest Forest Pass or Interagency Pass is required at most trailheads.
  • The South Fork Stillaguamish corridor is one of the most-visited day-use stretches in the Cascades on summer weekends. Arrive early at popular trailheads or expect to park well down the shoulder.
  • The gravel section is narrow, single-lane in places, with limited turnouts. Yield to uphill traffic.
  • The Big Four Ice Caves themselves have killed visitors who walked inside; stay outside the cave openings.
  • Cell coverage drops out east of Verlot.
  • Glacier Peak Wilderness trailheads need advance route planning; conditions change fast in late summer.

Frequently asked

Common questions

How difficult is Mountain Loop Highway?
Mountain Loop Highway is rated easy. The route runs 55 miles.
What kind of vehicle do you need for Mountain Loop Highway?
Standard high-clearance vehicle. Two paved segments are passenger-car friendly; the 14-mile gravel middle section is single-lane and rough but passable in stock 4x4 or higher-clearance 2WD in dry conditions. Trailers and RVs not recommended on the gravel.
When is the best time to visit Mountain Loop Highway?
The best months are Jul, Aug, Sep, Oct. Avoid Nov, Dec, Jan, Feb, Mar, Apr.
Is there cell service at Mountain Loop Highway?
Patchy near Granite Falls, Verlot, and Darrington. None on the gravel middle.