Hike one of the deepest, wildest, and most accessible wilderness valleys in the North Cascades National Park Complex. Let Thunder Creek's incessant bellowing woo you into this primeval pocket. Enjoy scenic creekside resting posts perfect for whiling away the afternoon. Admire ancient cedars and towering firs and, from holes in the thick forest canopy, gaze out to jagged peaks cloaked in glacial ice. And while the surrounding high country is blanketed in white, enjoy this hike early or late in the season thanks to its low elevation.

A large information board greets you at the trailhead and it's worth a gander before setting out up the valley. Yes, this is cougar country and necessary precautions should be exercised. But for your first mile or two, you'll probably need to be more concerned with saying hello to the throngs of people who venture out from the campground.

The wide, smooth trail immediately enters an impressive stand of old-growth forest. Hugging the thickly forested shore of Thunder Arm, an aquatic protrusion of Diablo Lake, the trail passes the Thunder Woods Nature Trail, a recommended diversion. On still mornings and evenings, catch glimpses of emerald ridges reflected in the placid turquoise waters of Thunder Arm.

Continue on a near-level course under giant firs and cedars and past big boughs of ferns, reaching Thunder Creek in about 1 mile. Soon new tread is encountered where the trail was rerouted in 2004. The old steel suspension bridge that once crossed Thunder Creek and that many hikers thought was sturdy and reliable evidently wasn't. The destructive floods of 2003 claimed this span along with many others throughout the Cascades and Olympic Mountains.

Continue alongside the west side of the creek, passing several inviting gravel bars. At 2 miles the trail comes to a new bridge. Pass through Thunder Camp, set in a centuries-old grove of behemoth firs.

Leaving the riverside, the trail now travels through a much younger forest and at 2.5 miles comes to a junction with the Fourth of July Pass Trail. Proceed right, cross a creek, and in 2.8 miles come to a junction with a short side trail that drops back to the river, landing in Neve Camp-a nice place to call it quits if you're content not to carry on.

Those inclined to experience more of the Thunder Creek valley can continue following the trail deeper into the wilderness. The thundering waterway is nearby the trail, always audible but not seen. Undulate between old-growth groves and younger forests that are replacing stands scorched by fires over the last few decades. Enjoy periodic openings in the dense canopy and impressive views of the array of towering peaks that line the valley. Their extensive glacial systems help feed the roaring creek beside you.

At 6 miles and only 1900 feet elevation, come to the junction with the side trail to McAllister Camp. This is a good place to call it a day, though you may still want to push the 0.5 mile to the camp to get a good glimpse of the narrow gorge where McAllister Creek roars into Thunder Creek. Savor the wildness. Return when you must.