The Diablo Lake Trail isn't well known, but it is a fantastic hike with a wide array of features throughout it's course.
Located in the North Cascade Mountains along Highway 20 between Marblemount and Winthrop, the Diablo Lake Trail allows hikers to get 'up close and personal' with the Diablo Dam, Ross Dam, Diablo Lake and also the awesome North Cascade Institute.
Although the trail is quite a drive from the I-5 corridor, there are campgrounds nearby at Colonial Creek and near Newhalem. Alternatively, consider registering for a class or an overnight at NCI to turn your hike opportunity into an unforgettable educational experience too.
The excitement of this trail literally starts before you even exit your car as you exit the Hwy 20 route to descend the impressive connector road that allows you to drive across the top of Diablo Dam. This short connector road can be terrifying to some as it's narrow (but paved) path has 100+ foot tall cliff towering above you on one side and a 100+ foot drop off down the other side. Then, throw in a skinny bridge over a tumbling creek and some people will be pondering who in the world decided this was 'a good idea'.
Drive over the gothic Diablo dam, stop for photos and to peek over the edge (and maybe kiss the solid ground) before following the road to the parking lot at NCI. This is where you'll find the official trailhead.
At this point you may be wishing that you had brought your kayak instead of your hiking boots... but you can come back for kayaking another day (it too is a fantastic route with a different perspective).
The trail is about 3.75 miles and a net of about 1,000 feet of elevation gain... one way. 7.5 miles and a net gain of 2,000 square feet are required if you are expecting to hike out and back. This is an important detail to note because at this point in time, an 'out and back' hike is the only option for most hikers.
Once upon a time, hikers were able to hike out to the end of the trail, cross the lake on a suspension bridge and then either hike up to Hwy 20 (to your strategically parked 2nd vehicle or to hitchhike back to the start) or... to catch the ferry back to the trail head.
A Ferry? Yes. A Ferry. Twice a day there is a boat that makes a round trip up the lake to haul the dam workers from Diablo Dam up to Ross Dam and vice versa. Once upon a time hikers could pay a reasonable price to catch a ride on the boat.
These days that isn't an option.
Due to a large landslide a number of years ago, the Ross Dam side of the bridge has been off limits to hikers... the cliff remains unstable and a large sign at the end of the bridge announces DANGER, Authorized Personnel Only.
It's a shame that this option isn't available because it makes for a wonderfully memorable return trip.
Don't be saddened though, your return hike involves a bunch of scenic views that you didn't notice on your way in because your back was turned to them.
Plus, you might get to encounter the bear that you may have missed on your way in. Hopefully you meet him where the trail is wide... not one of those spots with a high cliff up on one side and a long drop to the lake on the other side. Yeah, it's possible.
Anyway, the trail starts off routing around the NCI campus, passing pretty close to a few of their dorm buildings and passing through a few trail intersections which were signed 'pretty well' in most cases. If you have extra time and energy, consider following the Sourdough Creek trail to the falls on your way back from Ross Dam.... or make your way to Buster Brown Flats for another view of Diablo Lake.
The Diablo Lake trail will route you through the woods, over a couple creeks, keep your eyes peels for signs of mountain lions, and soon you'll reach a boulder/talus field. The trail is easy to follow, although there is a little bit of rock-hopping that may be required, and watch your footing so you don't turn an ankle.
The trail begins to gain elevation as it is force higher and higher above the lake simply due to the local topography as Diablo lake is channeled into a narrow gorge as it gets closer and closer to Ross Dam. Imagine what it might have looked like before the dams were in place... a rugged and wild world for sure!
Cliffs rise. Views open up to Pyramid Peak, Colonial Peak, Diablo Lake, Hwy 20... absolutely awesome! Take pictures... cherish the adventure you are on!
Eventually you'll pass under some powerlines (expect them... you're hiking from one dam to another of course) and then the trail will begin to descend to Ross dam. Be sure to visit the view points on your way down.
Explore the old structures and artifacts that litter the trail at the lake level. Check out the clear swatch of trees all the way up the mountain... that's an avalanche chute you are standing in.
Cross the suspension bridge. Check out the landslide. Check out the tunnel. Check out the color of the lake. Imagine having a job working at Ross dam. What a life!
Eat lunch. Hike back (and ponder the impressive ferry ride you SHOULD be on). Watch for bears.
Life is good.