Pets allowed
Not Allowed
Elevation Gain
4,870.00 ft (1,484.38 m)
Trail type
10.40 mi (16.74 km)
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Driving on Highway 20 through North Cascades National Park, the mountains tower high above on both sides. Getting up any of them seems like a daunting task from the asphalt, but that’s exactly what the trail to Sourdough Lookout (5,985 feet) offers. The reward: an excellent workout, nice views, wildflowers and a nice day enjoying the outdoors.

Start at the trailhead located in Diablo, a few hundred feet from Gorge Lake Campground. Cross a bridge after a quarter-mile hike. The creek might be the last reliable source of water in late summer or when it’s been dry for an extended period. You might want to fill up because the trail gains elevation fast and steadily.

The ascent is long and grueling. The dusty trail switchbacks through a forest of conifers that progressively thins, leading to more colorful wildflowers. At a little over 4 miles, Sourdough Camp is reached, which is the spot for those making this outing into a backpacking trip. Sourdough Creek is a few hundred feet farther, but the water is scarce in late summer. Carrying a straw and filter is a wise move.

From there, a mere mile separates hikers from the Sourdough Lookout Tower, most of which is on the rather flat, rocky summit. The lookout tower, which used to be a fire tower, is not located on the true summit, which lies about 1 mile northwest. No maintained trail goes to the true summit, but it’s an easy scramble for motivated hikers. There are views all around, most notably of the Picket Range, Davis Peak, Diablo Lake, Jack Mountain and Ruby Mountain.

The return trip is via the same trails used for the ascent. Make sure to adjust the trekking poles for the descent to give your knees a break.

Logistics + Planning

Preferable season(s)




Parking Pass

Not Required


Great views. Options for backpacking. Historical site.



Trailhead Elevation

1,115.00 ft (339.85 m)


Backcountry camping
Bird watching
Big vistas


Nearby Adventures

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

Nearby Lodging + Camping

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


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