Thornton Creek

Thornton Creek is located within Ross Lake National Recreation Area in Whatcom County, Washington. It is a tributary of the Skagit River. Thornton Creek is sourced from Thornton Lakes—three alpine paternoster lakes in a cirque below Mount Triumph's south ridge (which ends in a minor peak that has been called Thornton Peak) and Trappers Peak. It is one of the best canyons in the region and can be very challenging in high flow due to multistage rappels and hydraulics. Thornton can be broken down into 3 sections.

Shuttles: depending on the particular flavor of Thornton your running you can use either the top trailhead, pullouts at the 4th switchback above the bridge, pullouts at the bridge itself, or the highway 20 pullout, to position your vehicles. To access the start of the canyon take the Thornton Lakes Road and park at the Thornton Lakes Trailhead. You can either "half suit" up at the parking lot, or carry your wetsuit in your pack down to the entrance of the canyon. From the parking lot, head back toward the road, and look for pink flagging tape or a faint user trail on your left. If you find yourself walking down the road proper, you've gone too far. From here, follow the grade down, trending East-North-East until you reach the creek and find an easy way to enter the creek and a good spot to finish suiting up. Take the Thornton Lakes Road up the mountain for 1.25 miles and park where the road makes a sharp left turn (and where the road is closest to the river). It's the 4th switch-back after the bridge. Hike up the west rim of the canyon. At an elevation of 1380ft (48.65176, -121.31392) you'll meet an old forest road, which followed north-west will lead to the canyon. If you're looking for an extra-short route follow the west rim of the canyon to an elevation of 1200 feet and drop in down a steep hillside.

Caution: In higher water levels, canyoneers will be required to do a number of pothole escapes in hydraulics. Be aware that the rock is super slippery, the water is very cold, and some of the potholes do not have good handholds. This requires mantling with the hands and doing a beached whale move to get up and out while on rappel. There are also many jumps and slides in this canyon, many of which require precise spotting. Someone experienced in the canyon is vital, or each will need a good spotter to check pools for depth and obstacles. Descend a series of small down climbs and slides, mostly DCL Series of 5 slides, DCL first one is shallow, last one is a dry slide. Slide DCL Downclimb DCR then jump 8' Short slide, then downclimb DCL. It is possible to jump tight to the wall DCR, instead of the down climb, but it is a very technical jump due to a boulder in the pool, and a spotter is recommend if attempting it Slide DCC, with a ~12' drop off. Set an approximately 20' retrievable guideline from a rock pinch DCR across the flow to an anchor DCL This drops you into a deep pool that has a great spot to stop for lunch or a snack on the other side. There's also an old forest road which crosses the canyon here (48.6523441, -121.3148630). This can be used an escape option, or drop-in to run only the classic section. 15' Jump Series of small down climbs and slides Slide/downclimb Slide/downclimb The next rappel is on the edge of the pour-over in front of you. A traverse line can be rigged from anchors DCR to make access safer. [The flow checkpoint trail is now in sight]. Slide the slab to exit the final pool, and down-climb back to the bridge. This is the section below the bridge.