Pets allowed
Elevation Gain
600.00 ft (182.88 m)
Trail type
3.50 mi (5.63 km)
Please respect the outdoors by practicing Leave No Trace. Learn more about how to apply the principles of Leave No Trace on your next outdoor adventure here.

Many North Cascade hikes require some tradeoffs for views of the so-called “American Alps," whether in the form of long, bumpy forest roads or long, knee-busting trails that are only accessible a few months out of the year. Not so with Thunder Knob. This ominously named trail is much shorter and easier than it sounds, at only 3.5 miles round trip. Best of all, there are no forest roads to worry about because the trailhead is right off Highway 20, and the hike is accessible year round.

Thunder Knob trail begins at the north loop in Colonial Creek Campground. This location makes it a great option for campers, who can walk from their site to the trailhead in minutes. From the parking area, head north past a few campsites to cross a bridge over Colonial Creek. Fed by Colonial Peak's glaciers, the creek flooded in 2003 and 2006, causing irreparable damage to several campsites. Walk through the rocky, dry creek bed before entering a forest of western hemlock.

At 1 mile, views open up to Colonial Peak in the south. The landscape begins to change here: hemlock gives way to lodgepole pine, and the soil becomes noticeably drier, both effects from the rain shadow. At a junction, head left for the first of two Diablo Lake viewpoints. Davis Peak and McMillan Spires are visible to the west, while Sourdough Mountain rises from Diablo Lake directly north. Back at the junction, continue to the second viewpoint for a glimpse of Jack Mountain through the trees. You can even peer down on Diablo Lake Overlook from here.

Logistics + Planning

Preferable season(s)




Parking Pass

Not Required


Nice views over Diablo Lake. Open year round.



Trailhead Elevation

1,200.00 ft (365.76 m)


Bird watching
Big vistas


Nearby Adventures

Ross Lake National Recreation Area, North Cascades National Park
Ross Lake National Recreation Area, North Cascades National Park

Nearby Lodging + Camping

Ross Lake National Recreation Area, North Cascades National Park
North Cascades National Park
Ross Lake National Recreation Area, North Cascades National Park


Great hike! Started a bit late in the morning and felt the heat after the first vista (facing SW). At the top there are two viewpoints. Spend time at both. A bit tough for the little one (7 y.o.) due to the heat but making it to the top was so rewarding. Trail did have creek crossing and some rocky terrain so hiking boots are reccomended.
This is a nice little hike that leads right out of the North Side of Colonial Creek Campground. Because of the fires in BC, the views were fairly limited but you could see hints of what would be gorgeous views on a clear day. There's are several benches along the trail that offer a nice place to sit and take a break if needed. Overall, a nice, low-key hike.
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