Pinch me. A hike with major mountain views without a major climb. Awesome overhead vista of Diablo Lake with Davis Peak and crab-claw-looking McMillan Spires to the side. And, get this, real benches – on the trail as well as the summit. A perfect hike? Mostly. You’ll have to read below for the exceptions.

The Thunder Knob Download

Highlights: Mountain views, dog friendly, great view of Diablo Lake, benches.

Travel Time (from Urban Centers to Park/Trailhead): 2 ½ hours from Seattle, 2 hours 45 minutes from Vancouver, B.C.

Nearby Supplies and Gas: Marblemount west, Winthrop east.

Difficulty: Most including children should be able to hike this without being too taxed. Some guides say the trail is wheelchair accessible, but only in terms width of trail; surface is too uneven and grade may not be optimal. Small lodgepole pine may block trail after severe weather, but usually is easy to navigate.

Distance: 3.6 miles.

Entrance Fees: None (!).

Top Elevation: 1,875 feet.

Elevation Gain: 425 feet.

Trailhead Waypoint: 48.6905, -121.0980

Maps: Green Trails Diablo Dam No. 48; USGS Ross Dam.

Getting There: From I-5 take WA-20 East, about 24 miles past Marblemount (or 63 miles west of Winthrop) on North Cascades Highway. Just past milepost 130, the Colonial Campgrounds will be on left. Trailhead parking is right of campground entrance.

Know that joint where you feel so comfortable and like to hang, practically until someone has to kick you out? Thunder Knob is that kind of place. Anywhere that has (13, see below) benches set in front of gawkable views is a hang. And you know I’m bringing lunch, so I’m really not leaving.

Until I have to go to the bathroom, maybe. Thunder Knob maybe is an outhouse short of perfection.

Well, not really. This hike would be close to perfect if you could, say, take it in any season. I mean, it’s a great hike for the winter. The elevation is low enough that it doesn’t get much snow, and it’s an easy, actually enjoyable, ride over.

You know there’s a “but,” and it’s that the park service removes the footlogs across Colonial Creek (see video) in early November. It’s disappointing but understandable since the creek went haywire in 2003 and 2006 and flooded big time, enough to alter its course. You can see the remnants in the alluvial fan (sediment left by streams and built in the shape of … yeah, you guessed it) just steps into the hike.

Point is, the creek can rise unpredictably, especially after stormy weather, and take the footlogs with them. I did this hike right after the logs were removed; it means assessing the creek’s speed and depth and fording it (I crossed waterproof boots and gaiters; trekking poles may have helped, but I left mine at home).

After the rocky alluvial fan, the trail goes through a forest of fir, cedar and hemlock. About a mile in is a bench with a spot-on view of perpetually snow-capped Colonial Peak. You can tell you are in a rain shadow because of the lodgepole pine and kinnickinnick, both of which can grow in dry, shallow soil.

Before the top is reached, there is a slight drop into what I thought of as pond valley, also thoughtfully adorned with strategically located benches. At the summit, there’s first a spur trail left to the wonderfully turquoise Diablo Lake, Davis Peak and Sourdough Mountain westward viewpoint, then one right for a southbound peep at Colonial and Pyramid peaks, and then straight to the end and a northeast glance at massive Jack Mountain and Ruby Mountain.

The top screams for a picnic, by the way. There are six benches up there, each with a scintillating view to be consumed with a meal.


No. 1: half-mile in, at the end of a switchback, nice shade with view of Diablo Lake.
No. 2: three switchbacks and a short, exposed stretch later.
Nos. 3 & 4: emerging from mostly forested to a big view of Colonial Peak.
No. 5: overlooks the largest pond.
No. 6: nearly pondside.
No. 7: View of Colonial Peak & Ruby Mountain.
Nos. 8 & 9: down a spur trail to the left, views of Diablo Lake, Davis Peak, Sourdough Mountain.
Nos. 10 & 11: clearing with Colonial & Pyramid Peaks.
Nos. 12 & 13: at end of the trail, views of Jack & Ruby Mountains.

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