The Mountain Loop Highway (officially, Forest Route 20) is a two-lane, 52-mile, partially paved highway in Washington State that connects the towns of Granite Falls and Darrington. Between May and September, the Mountain Loop Highway offers a pleasant, day-long summer drive for outdoor photographers, hikers, and nature enthusiasts.

Almost the entire highway traverses the Mount Baker-Snoqualmie National Forest. Despite its name, the highway itself does not form a full loop but does, however, connect to State Routes 92, 9, and 530 to create a longer, total loop.

Understand

See also: Washington state

Ringing a series of interesting geographic features known as "the interior", the Mountain Loop Highway is jointly maintained by Snohomish County and the United States Forest Service. Established in 1936 from a series of disconnected, primitive wagon roads that once linked remote mining and logging settlements in the area, construction on the route was completed in 1941. The highway was closed during World War II and, again, from 2003 to 2007 due to torrential rains that destroyed large sections of the road.

The Mountain Loop Highway encircles several geographic features, including Whitehorse Mountain (pictured).

Today the Mountain Loop Highway is largely used as a scenic drive and to access trailheads in the Mount Baker-Snoqualmie National Forest. The highway also serves as a "backdoor" evacuation route for Darrington, which is outwardly connected by only one other road. The town could be threatened by an eruption of nearby Glacier Peak, one of five active stratovolcanoes in Washington.

Plans to complete the unpaved section of the highway in the 1980s, 1990s and 2010s met with local opposition and approximately a third of the road remains unimproved to this day.

Prepare

A portion of the highway is unpaved gravel road. While high-clearance or four-wheel drive are not necessary, motorcyclists should exercise caution.

The unpaved section of the highway is closed for the winter in November or December, depending on weather, and generally reopens in May.

There are no gas stations between Granite Falls and Darrington. Take adequate fuel to make the journey.

There is little-to-no cellular signal between Granite Falls and Darrington.

Camping

The U.S. Forest Service maintains several campgrounds along the Mountain Loop Highway. There are also dozens of unmarked (but easily identifiable) dispersed campsites. Many of these are along the highway, especially on the unpaved section along the Suiattle River. These unimproved single-tent sites offer a more intimate and remote setting than the parceled slips of the improved campgrounds. The highway receives practically no traffic after dusk. Dispersed sites are free, but fill up fast on summer weekends.

Backcountry camping generally allowed and free for those hiking away from the road, with the exception of the Monte Cristo townsite.

Firewood can be purchased from grocery stores and convenience stores in Granite Falls and Darrington. As with much of the American West, open-fire burn bans are common during the summer.

Fees and permits

Most of the land along the Mountain Loop Highway is regulated by the U.S. Forest Service. A parking pass is not required to drive the highway, or for short-term parking at designated scenic outlooks, but most other recreation requires one of the following passes to be displayed on each vehicle:

• United States Interagency Annual Pass ($80 online, valid for unlimited use at all United States National Parks, National Forests, and National Monuments for one-year)
• Northwest Forest Pass ($30 online, valid for unlimited use at all United States National Forests in the states of Washington and Oregon for one-year)
• National Forest Recreation Day Pass ($5 online and valid on one self-selected day only).

Get in

While this itinerary describes driving from Granite Falls to Darrington, the route can be taken in either direction.

To reach 1 Granite Falls, and the start of the Mountain Loop Highway, drive north from Seattle along Interstate 5, exiting north of Everett on U.S. Highway 2. Follow U.S. Highway 2 to the east and continue to Washington State Route 204 which becomes Washington State Route 9. Continue on State Route 9 for approximately 1.75 miles and then turn right onto Washington State Route 92, commonly called the Granite Falls Highway. Follow this into Granite Falls, where it turns into Stanley Street.

Once in Granite Falls, continue down Stanley Street, then turn left onto Alder Avenue and then drive north approximately 0.25 miles. On your right side you will see Granite Falls Middle School. It is here that Alder Avenue becomes the Mountain Loop Highway.

Drive

The first 1.5 miles of Mountain Loop Highway takes you through the residential outskirts of Granite Falls. The town limits end approximately at the 1 Granite Falls Fish Ladder. When it was built in 1954, the fish ladder was the world's longest vertical-baffle fish ladder. There is a small, gravel lot next to a staircase that leads down to the fish ladder. Park here and venture down to see both the ladder, and the shallow, rock falls for which the town was named.

11 miles from Granite Falls is the 1 Verlot Public Information Center. You can purchase your parking passes here. From here, the highway closely follows the Stillaguamish River as the valley becomes narrow and rugged, and nearly every mile provides a popular trailhead, campground, or fishing hole. 1 Mount Pilchuck State Park features a trail to the top of Mount Pilchuck (5324') with breathtaking views in all directions. 2 Lake 22 is another popular day hike, and the trailhead fills up early.

You will next pass the single-lane bridge to 2 Silverton, a small, residential settlement with no businesses or services.

Two miles beyond Silverton, a highway exit on the right side of the road leads to the 2 Big Four Ice Caves. Parking is available in a paved lot while a short and easy, 45-minute hike leads to the ice caves which can be viewed from a terminal lookout.

The pavements ends 3 Barlow Pass. Here, there is a trailhead to the abandoned mining town of 3 Monte Cristo. The trail to the townsite is eight miles, round-trip. Many century-old structures still stand, including the railway turntable.

The Monte Cristo townsite pictured in 2014

Turn around here, or continue onto the gravel road, as the highway turns northward along the Sauk River. The pavement returns before reaching the Sauk-Suiattle Reservation, then continues on to 3 Darrington. The Mountain Loop Highway ends at the junction of State Route 530.

Stay safe

At the Big Four Ice Caves, do not leave the trail to illegally enter the highly-unstable caves. Sudden cave-ins have taken several lives since 2010, making it one of the most dangerous hikes in Washington, despite the completely avoidable danger.

The Cascades are habitat for black bears. There have been fewer than a dozen bear attacks in Washington in the last century, but hikers need to know about bear safety. Ask a park ranger for local advice.

Go next

From Darrington, drive west along State Route 530 to Interstate 5, which travels a paved road with a standard speed limit and will be faster than returning the way you came.

For more mountains, instead drive north along State Route 530 to reach State Route 20, then head east to North Cascades National Park.

From I-5,

• Seattle is an hour south, and Vancouver is less than two hours north
• Enjoy the Salish Sea from Anacortes, Camano Island, or Whidbey Island