5.0
(1)
25
hikers
Thunder Knob Trail
00:56
3.02km
180m
Hiking
Embark on the easy Thunder Knob Trail, a 1.9 miles (3.0 km) hike that takes about 56 minutes to complete, with a gentle 596 feet (182 metres) of elevation gain. You will begin by winding through a lush, moss-covered forest, following the turquoise Colonial Creek. Cross a unique "1-At-a-Time" footbridge before the path ascends into drier lodgepole pine forests. The route offers several viewpoints with expansive vistas of Diablo Lake and alpine peaks like Sourdough Mountain. The vibrant turquoise hue of Diablo Lake, visible from the summit benches, is a striking feature.
This family-friendly route is well-maintained, making it suitable for a wide range of hikers. You can find parking conveniently located near the Colonial Creek Campground, which serves as the starting point for your adventure. Its lower elevation also makes it a good option for hiking during the off-season, when higher trails might still be covered in snow.
Located within the Ross Lake National Recreation Area, the Thunder Knob Trail is notable for its unique views of Diablo Lake. The lake's distinctive turquoise color is caused by glacier-scraped rock flour, a natural phenomenon that sets this landscape apart. It is a popular route, offering a chance to experience the region's natural beauty even when other, higher elevation trails are inaccessible.
Last updated: April 23, 2026
Tips
Your route passes through a protected area
Please check local regulations for:
Waypoints
Start point
Parking
Get Directions
1.55 km
Viewpoint
Viewpoint
2.87 km
View of Diablo Lake
Highlight • Viewpoint
Tip by
2.88 km
Thunder Knob Trail
Highlight • Trail
3.02 km
View of Diablo Lake from Thunder Knob Trail
Highlight • Viewpoint
Tip by
3.02 km
End point
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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Weather
Powered by Foreca
Wednesday 6 May
18°C
8°C
14 %
Additional weather tips
Max wind speed: 6.0 km/h
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This route was planned by komoot.
Frequently Asked Questions
How challenging is the Thunder Knob Trail?
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.
What kind of views can I expect along the route?
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.
Is the Thunder Knob Trail an out-and-back or a loop?
This is an out-and-back trail. You'll hike to the viewpoints and then return along the same path to the trailhead.
Where can I park for the Thunder Knob Trail?
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.
Are dogs allowed on the trail?
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.
What is the best time of year to hike this trail?
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.
Do I need a permit or pay an entrance fee for the Thunder Knob Trail?
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.
What kind of terrain will I encounter?
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.
Does the trail intersect with other paths?
Yes, the route primarily follows the Thunder Knob Trail itself. It also briefly intersects with sections of the '10 (Washington)' trail.
What's an insider tip for hiking the Thunder Knob 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.
Is there water available on the trail?
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.