Wandering White River
on Mt Hood
Part I.
The White River begins on the south slope of Mt Hood from the terminus of the White River Glacier as two branches separated by a moraine that stretches down the mountain, widening and flattening at an area known as Mesa Terrace. Ancient Trees from a forest buried under pyroclastic debris during the last major eruptive period are visible in the walls of the canyon here, best seen from the Timberline Trail/PCT on the ridge to the west. The right branch, the main stem of the White River, is joined by a drainage from snow fields between White River Glacier and Newton Clark Glacier. The two mighty branches flow past the Timberline Trail circling Mt Hood, and join together above where the river flows under Highway 35. From there it continues south, before curving to the flow east and into the Deschutes River which flows north to the Columbia.
In the wide floodplain around the highway crossing on the south side of Mt Hood, the river is in constant evolution, carving new paths and excavating material, wandering around in the deep lahar deposits. Recently the river has been moving east, and last winter a huge relocation happened after during a high water event, where the river flooded the Sno-Park before carving a new course on the eastern edge of the canyon, flowing now under the overflow bridge and not the main span of the highway bridge. The WyEast Blog has an exemplary history of battle between river and highway infrastructure.
Wanting to have accurate views of the location of the river, especially in relation to mapping the Timberline Trail crossing, I set out to wander along the river and record it's track.
(I hadn't found any recent high resolution imagery to use for tracing and just after realized Google had updated it's Google Earth Imagery to 2021 images (although not yet the Google Maps. Had I opened up Earth instead of just maps, I could have saved the extensive wandering, but it was a lovely excursion.)
Starting from White River Sno-Park mid afternoon, I headed up the snowshoe route/trail. I got distracted by the sound of water pouring down the hillside, coming off of Boy Scout Ridge, and ducked into the a thick layer or alders and brush looking for anything interesting. A nice mossy small drainage.
I continued heading north to the Timberline Trail junction, and then crossed both branches, both doable with the current flow rate without getting feet wet by using rocks to cross. Then I crossed back and headed upstream between the branches, hugging close to the east branch while GPS tracking to get close to it's location. My phone GPS hovers around +/- 12 to 15 feet in open terrain like this, so I made notes of which side I was on to later help clean up the data. Navigating around in the river valley it is amazing to see the winding, wandering dry sections cutting through deposits, evidence of the past motions of the river. Some immense piles of debris and huge boulders are testament to the power of the river in a flood stage. Looking at this area in Google Earth now is interesting, as the discrepancy between the recent aerial imagery and the elevation data used to generate the terrain in three dimensions makes the river seem to flow uphill and downhill, highlighting the significant changes by erosion.
Timberline Trail Crossings
I got intrigued by the smaller, furthest east branch that flows into the main White River, and headed up the steep area between the two, drawn by a glimpse of the Lower Dryer Falls off in the distance. This side journey took me across the creek where I saw the work of beavers in the vegetated, protected drainage. The valley here cuts through an imposing layer of lava flow that sets a very picturesque scene.
After this scenic diversion, I headed back and began walking the branches of the creek, retracing steps to get both branches, and then walking the creek from where they joined south of the Timberline Trail crossing. The sun started to lower, casting warm light on the canyon as I neared the bridge on highway 35. Some of the sections where the river shifted to the east along the canyon wall have freshly cut deep walls showing the layers of deposited material from past movements.
buried forest exposed by the new river course
Following the river course here was an enlightening view of the constant change and power of the river here, coursing down from it's glacier source, the destination for my next wandering of the White River.