River Loop Trail: 1.8-Mile Forest Walk, North Cascades

Quick Information

The River Loop Trail is free to access, as is the entire North Cascades National Park Service Complex. The trailhead is open year-round, but conditions vary dramatically. The best time to visit for a dry, predictable walk is from late June through September. The trail is located in Washington State, off the North Cascades Highway (State Route 20), roughly 15 miles east of the town of Marblemount. The flush toilet at the trailhead is a notable amenity for this stretch of highway. Parking is limited to a paved pull-out that can accommodate about a dozen vehicles and a couple of RVs; it's often full by mid-morning on summer weekends. Cell service is unreliable and typically drops out at the trailhead.

Getting There

From the west, take Interstate 5 to Burlington, then head east on State Route 20 (the North Cascades Highway) for about 46 miles. The trailhead is on the south side of the highway, roughly 5 miles east of the Colonial Creek Campground area. Look for a signed pull-out. From the east, the trailhead is about 60 miles west of Winthrop, but note that State Route 20 is closed seasonally from roughly November to May between the Ross Dam Trailhead (milepost 134) and the Silver Star Gate (milepost 171). As of 2026, there is an active closure at milepost 130 (Colonial Creek), so always check the Washington State Department of Transportation website for real-time road status before you go. The parking situation here is first-come, first-served.

What to Expect

Expect a gentle, rolling trail with minimal elevation gain—about 100 feet total. The path is a classic Pacific Northwest forest walk: soft underfoot with dirt, pine needles, and exposed roots. The air carries the scent of damp earth and cedar. You'll cross a few sturdy footbridges over seasonal streams. The main draw is the series of viewpoints along the Skagit River, where opaque, glacial-green water churns through boulder gardens. Trail conditions are generally good but can be muddy in spring and slick with wet leaves in fall. For solitude on the riverbanks, aim for early morning; the low light through the trees justifies the early start.

Top Attractions & Points of Interest

While the River Loop Trail itself is the attraction, it's a gateway to the broader park. The loop is simple: from the trailhead, you can go either direction, as it's a true loop. Most hikers go clockwise for a slightly more gradual descent to the first river viewpoint.

The Skagit River Viewpoints

There are three main spots where the trail edges close to the bank. The first, about 0.4 miles in, gives you a head-on view of the river's power. The second, near the midpoint, is a wider, gravelly area where you might see driftwood piled high from spring runoff. The third is the most secluded, a quiet bend where the water slows momentarily. From these overlooks you can see the opposite forested bank and, if you're lucky, an osprey circling overhead.

The Old-Growth Forest

The trail doesn't just go to the river; it meanders through a mature conifer forest. Look for massive Douglas firs with furrowed bark and the shaggy, reddish bark of western red cedars. Rangers will tell you this forest type is a hallmark of the lower Skagit River valley.

Proximity to Colonial Creek

The trailhead is just minutes from the Colonial Creek South and North Campgrounds, making it a perfect after-dinner stroll for campers. The sound of the nearby creek adds another layer to the soundscape.

Activities

The River Loop Trail is primarily a day hiking destination. It's ideal for families, those seeking a leg-stretcher during a long drive on SR 20, or photographers looking for intimate river scenes without a strenuous hike. Its easy grade makes it suitable for most fitness levels. While you're in the area, the park offers countless other hiking trails for more ambitious adventures.

The broader park complex is a hub for water activities. The nearby lakes - Diablo, Gorge, and Ross - are popular for paddling in the North Cascades and motorboating. The Skagit River itself, which you see from the trail, is a known destination for rafting, especially in summer. Fishing in the North Cascades is also popular in the many lakes and rivers.

Seasonal Guide

June - September: The trail is in prime condition. Dry, clear, and buzzing with insects (bring repellent). This is high season; expect company.

October - November: A quieter, moodier time. Fall colors light up the understory of vine maple. Trails can be slick with wet leaves and occasional frost in the morning.

December - May: The trail is often snow-covered and inaccessible due to the seasonal closure of State Route 20. Even if the road is plowed to the trailhead, expect packed snow and ice; microspikes are recommended. Always check the best time to visit for current conditions.

Practical Information

There is no entrance fee or permit required for this day hike. For camping options, the nearest are Colonial Creek South ($24/night, 93 sites) and Colonial Creek North ($24/night, 38 sites). Both are first-come, first-served and fill quickly in summer. Other nearby frontcountry campgrounds include Goodell Creek and Newhalem Creek. For lodging and accommodations, you'll need to look to the towns of Marblemount to the west or Winthrop to the east. There are no services at the trailhead beyond the restroom. The last reliable gas and food are in Marblemount.

Safety & Preparation

This is a low-risk trail, but standard rules apply. Pack extra water for this stretch, even though it's short - there's no potable water at the trailhead. The river is cold, fast, and dangerous; do not attempt to wade or swim. Be aware of your footing on the occasional root or muddy patch. As with all trailheads along SR 20, the park service has issued cautions about vehicle break-ins. Remove all valuables, electronics, and even charging cords from your car before you hike. Leave nothing visible in the passenger compartment.

Insider Tips

1. Reverse the Loop: If you want the river views sooner, hike the loop counter-clockwise. You'll hit the first big overlook in under five minutes.
2. Combine It: This trail pairs perfectly with a visit to the nearby Thunder Knob Trail (3.6 miles roundtrip) for higher lake views, or a stop at the Diablo Lake Overlook.
3. Listen for Wildlife: This is a good spot for wildlife viewing. Keep an eye out for pileated woodpeckers hammering on snags and listen for the croak of ravens.
4. Beat the Crowds: The lot is often full by 10 AM. Arrive before 9 AM or consider visiting in the late afternoon after the main day-use crowd has moved on.
5. Check Road Status Twice: First, check the WSDOT website for SR 20 closures. Second, check the park's alert page for any trail-specific or flood-related issues, especially after heavy rain.
6. The Gift of the Flush Toilet: That restroom at the trailhead is one of the few flush toilets on this section of highway. Use it wisely.
7. Post-Hike Stop: Drive five minutes west to the Colonial Creek area. The picnic spots by Diablo Lake are a superior place for lunch compared to the river pull-outs.

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For more information, see our complete North Cascades National Park Guide.