When one thinks of Whatcom County, they most likely picture bay views and berry fields, Mount Baker and the Nooksack River. The cities of Bellingham, Lynden, and Ferndale all come to mind. This is a wonderful place that attracts people from both near and far. But there’s another Whatcom County that exists and in that place lies outdoor adventure and picturesque views. This other Whatcom County is where you find the Thunder Knob Trail, your path to stunning views of mountain peaks and the incredible blue of Diablo Lake.
To reach this outdoor wonderland one must head east on Highway 20 towards Winthrop. For much of the drive you’ll find yourself in Skagit County before suddenly reentering Whatcom County. This scenic drive, also known as the North Cascades Highway, winds its way through mountains along rivers, and presents waterfalls around seemingly every turn. A gateway to sunny weather on the east side of the state, this path offers plenty for those who take the time to stop.
The Thunder Knob trail lies just off the highway, right before crossing the Thunder Arm of Diablo Lake. Colonial Creek Campground flanks both sides of the highway and it’s through the west side of the campground that you will find the Thunder Knob trailhead.
You’ll spot a sign—and parking—for the hike just off the highway and the starting point for a rather short and somewhat awkward walk through the campground, passing by campers as you go. The friendly campers seem used to the hiker traffic, which alleviates any anxiety that walking through someone’s campsite might produce.
The path to the trailhead is well marked and after crossing a small bridge over Thunder Creek, you leave the campground and are officially on the Thunder Knob Trail. The trail begins in a lightly wooded area with a slight grade heading up to the peak. As you travel along the trail, the forest becomes less dense and the trail steepens slightly.
You increase in elevation the entire time, but there are plenty of switchbacks on the 1.8-mile trek to the top. This combined with only 635 feet of elevation gain makes for a hike that never presents any overly steep grades. Combined with a round trip distance of 3.6-miles makes, this excursion is within reach of an inexperienced hiker. The trail is not overly strenuous and includes no treacherous areas that could result in a long fall, so it can be ideal for kids, as well.
Along the trail you’ll encounter plenty of locations that offer a gorgeous views, many with room to step off the trail and a few with a well-placed bench. As you gaze up, you’ll see mountain peaks holding on to pockets of snow deep into the summer and looking down take in the sight of chilly Diablo Lake below.
For most of the trail, your view is to the east, looking down at the Thunder Arm of Diablo Lake and to the south, looking across the valley to the peaks above. Along the way you’ll also spy different glimpses of Highway 20, giving you good perspective of how the road winds its way through the valley.
As you reach the top of Thunder Knob, the outlook opens up to allow 360 degrees of viewing pleasure. To the north you can now peer down at the greenish blue water of Diablo Lake and the snow crusted peaks above. The Diablo Dam, one of three on the Skagit River, and associated infrastructure can be seen in the distance, reminding you what it took to create this lake. Along the ridge there are benches placed so that each group has their own quiet spot from which to enjoy the view.
Once you’ve taken in your fill of the vista, it’s just a quick return hike to your vehicle. The sights are just as stunning on the way down and the new perspective makes the trek enjoyable.
The trail is a popular one, so expect to see other hikers. On my recent excursion, we encountered people along the route but hiked by ourselves the entire way. Most people wore masks, and everyone politely stepped out of the way for each other.
There’s no drinking water along the way, but there is an opportunity to fill up water bottles and use restroom at the campground. If along the trail you hear what you think are sleigh bells, these are in fact people wearing a low-tech way of ensuring you don’t startle a bear, which are known to frequent the area.
Hiking at a moderate pace and without spending an inordinate amount of time taking in the views, the hike will take around an hour and a half, leaving plenty of time to enjoy the other beautiful scenes in the vicinity.