Colonial Creek is, at first glance, a fairly discrete creek emptying into the placid waters of Diablo Lake's Thunder Arm. But looking up its valley from the right places one can glimpse portions of what is thus far the tallest waterfall recorded in the continental United States. As Colonial Creek drains from the lake forming in place of the retreating Colonial Glacier, it slides over the lip of the valley's headwall, plunging and skipping a total of 2,568 feet in 13 distinct steps before reaching the floor of the basin. Because of the height involved with the falls, as well as the fact that there are multiple steps and breaks in the consistency of the gradient, the falls have a considerable overall run (over 4,200 feet) which gives Colonial Creek Falls an average pitch of about 65 degrees. However, many of the distinct tiers of the falls are over 75 degrees in slope, with the uppermost drop starting out as a very steep horsetail, and the final tier of the falls breaking into two distinct segments, each featuring a 300 foot sheer free-fall.
Our initial estimate of the height (2,584 feet) was derived entirely from topographic data. When we surveyed the falls in August 2011, we were only able to get to withing about 3000 feet of the base of the falls. Using triangulation and the coordinates from the position we measured from, we arrived at a revised height of 2,568 feet. There is certainly a margin of error in this measurement, but it not likely to be off by more than 50 feet.
Colonial Creek heads in the Colonial Glacier, which is unfortunately quickly shrinking and being replaced with a small lake. The creek, though not large in volume, is fairly consistent and does flow all year long. The falls, however, heading at over 5500 feet in elevation, often remain half buried in snow well into the spring and early summer due to the elevation, so seeing the falls completely exposed and flowing at peak volume is usually not possible.
- Colonial Creek Falls is the Unofficial name of this waterfall.
- Known Alternate Names: Hiavaty Falls
We've heard from one source the falls are called Hiavaty Falls, but we have yet to hear back as to the origin of this name. It's possible this is a name bestowed by mountain climbers.
Located near Diablo Lake, within North Cascades National Park. Colonial Creek Falls can be best seen from two places. The first is the Ross Dam trailhead, 3/4 miles east of John Pierce Falls along Highway 20. More of the falls can be seen from this perspective, but at almost 5 1/2 miles away as the bird flies, the falls appear quite inconsequential. Look between and below Pyramid and Colonial Peaks to the south southeast. A better, closer viewpoint is on the east end of the Thunder Arm Bridge over Diablo Lake, just east of the Colonial Creek campground. The falls are only about 2 miles away at this point and a less powerful lens is necessary to get a good view. It is possible to get closer to the falls by following a very rough climbers route into Colonial Creek basin from Highway 20. The route climbs very steeply to the basin, at which point heavy brush prevents easy travel further. From Highway 20 to the base of the falls is about 1.5 miles, in which 2000 feet of elevation is gained. Because the climber's path is not at all consistent and this is in effect a bushwhack, I do not recommend it be attempted.