5.0
(1)
27
hikers
00:56
3.02km
180m
Hiking
The Thunder Knob Trail offers a delightful journey through varied terrain, starting near Colonial Creek Campground and winding through shady forests of fir and moss-covered trees. As you ascend, the path opens up to reveal stunning panoramic viewpoints of Diablo Lake's vibrant turquoise waters, colored by glacier-scraped rock flour, and the majestic alpine peaks beyond. You'll encounter a small pond near the top, adding to the scenic charm of this accessible route.
This easy 1.9-mile (3.0 km) hike, with 596 feet (182 metres) of elevation gain, typically takes around 56 minutes to complete, making it a perfect family friendly option. The trailhead is conveniently located off Highway 20 at milepost 130, near Colonial Creek Campground. While it's generally accessible year-round, always check for seasonal considerations like winter road closures on Highway 20 or potential flooding in the initial sections of the trail.
What truly sets the Thunder Knob Trail apart is its exceptional reward-to-effort ratio, providing significant mountain and lake views without requiring a strenuous climb. It's a popular choice for those seeking a leisurely afternoon hike or an outing with children, offering a taste of North Cascades National Park's beauty. The trail is also dog friendly, provided your furry companions are kept on a leash.
Last updated: June 9, 2026
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Waypoints
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Parking
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1.55 km
Viewpoint
Viewpoint
2.87 km
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2.88 km
Highlight • Trail
3.02 km
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3.02 km
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Way Types & Surfaces
Way Types
2.84 km
159 m
< 100 m
Surfaces
2.79 km
< 100 m
< 100 m
< 100 m
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Elevation
Highest point (560 m)
Lowest point (380 m)
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Thursday 2 July
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This route was planned by komoot.
The Thunder Knob Trail is generally considered to be of moderate or moderately easy difficulty. It features an elevation gain of about 425 to 675 feet spread out over switchbacks, making the ascent gradual and manageable for most hikers, including inexperienced ones and families with children.
The trail offers continuous and increasingly expansive views. You'll get stunning panoramic vistas of Diablo Lake, known for its vibrant turquoise color, as well as surrounding peaks like Sourdough Mountain, Davis Peak, Jack Mountain, and Colonial and Pyramid peaks. There are benches strategically placed at viewpoints for resting and enjoying the scenery, including a View of Diablo Lake and a View of Diablo Lake from Thunder Knob Trail.
This is an out-and-back trail. You'll hike to the viewpoints and then return along the same path to the trailhead.
The trail begins near the Colonial Creek Campground. Parking is available at the campground, and you'll walk through a portion of the campground to reach the official trailhead.
Yes, dogs are permitted on the Thunder Knob Trail, but they must be kept on a leash at all times. Please remember to pack out all pet waste.
The trail is enjoyable from spring through fall. Its lower elevation also makes it a viable option for hiking during the off-season when higher-altitude trails in the North Cascades are typically snow-covered. For the most vibrant turquoise lake views, a sunny day is ideal.
The Thunder Knob Trail is located within the Ross Lake National Recreation Area, which is part of the North Cascades National Park Complex. There are no entrance fees for North Cascades National Park or Ross Lake National Recreation Area. However, if you plan to camp overnight, backcountry permits are required. For day hiking, no specific permit is needed.
The trail starts by traversing through a lush, moss-covered forest with ferns and hemlock, alongside the scenic Colonial Creek. After crossing a '1-At-a-Time' footbridge, the path gradually ascends through switchbacks, transitioning into a drier forest of lodgepole pine with more rocky and exposed ground as you climb.
Yes, the route primarily follows the Thunder Knob Trail itself. It also briefly intersects with sections of the '10 (Washington)' trail.
To fully appreciate the distinctive turquoise color of Diablo Lake, plan your hike for a sunny day. The glacier-scraped rock flour in the water truly comes alive with the sun's reflection, making the views even more spectacular.
There is no potable water available directly on the trail. It is essential to carry enough water for your entire hike, especially on warmer days. Colonial Creek runs near the beginning, but filtering is recommended if you plan to use it.
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