Distance: Up to 12 miles RT, but even the first 2 miles make a fine destination
Elevation Gain: 1300 feet if you follow the trail deep into the valley; the trail is relatively flat for the first couple of miles.
Maximum Elevation: The trailhead is at 1240 feet; the first two campgrounds at Thunder Creek and Neve are just under 1400 feet.
Season: Spring through fall (though you can often make it a few miles down the trail in the winter)
Maps: Green Trails Diablo No. 48
Description: Starting at the southern end of the Colonial Creek Campground, this shady forest trail takes hikers deep into the North Cascades wilderness. From the beginning hikers will be walking among giant firs and cedars, with lush understory brush covering the forest floor. My kids enjoyed the maidenhair ferns and shy orchids, as well as finding old hollowed-out cedars. Look for the trail heading off to the right early in the hike for the 0.9 mile Thunder Nature Trail, which makes a fine destination for younger children. After about a mile and a half, the trail crosses Thunder Creek on a sturdy bridge, and you’ll find the first campsite there to rest or stay the night. That is as far as our family has gone, but there are more campsites farther up the trail. The trail does become more rugged the farther in you go. If you are planning to stay overnight, you’ll need to get a free backcountry camping permit from the Wilderness Information Center in Marblemount.
Directions: From I-5 in Burlington, take the exit for SR 20 and head east through Sedro-Woolley, Marblemount and Newhalem. Around Milepost 130 turn right into the Colonial Creek Campground and drive all the way to the back of the campground. You’ll see signs for the amphitheater and a trailhead sign for the Thunder Creek Trail. There is limited parking here; if it’s full, you’ll need to park out on the highway (there are ample spaces there) and walk through the campground. You will not need any parking permits.