Thursday, September 13, 2012

The Best Washington Geologic Rest Area

I do have a favorite Washington rest area. The south bound Intertstate 82 rest area just north of Selah is my favorite.

I-82 south bound rest area near Selah

First there is a great view of the concrete arch bridge across Selah Creek 325 feet below. A plaque indicates that at the time of construction it was the longest concrete arch span in the United States.  

Fred Redmon Memorial Bridge

Across the interstate from the rest area is Pushtay an odd hill that with a volcanic cone shape, but is an erosional feature pushtay-odd-hill-near-selah-washington.

Pushtay

A short walk to the north on a paved path provides great views down into Selah Creek canyon and the Selah Cliffs Natural Area Preserve managed by the Washington State Department of Natural Resources. This area has been set aside for protection due to several rare plants that grow on the steep slopes at the base of the cliffs.

Not yet well understood changes in the area the Columbia River cuts through the Cascade Range likely caused an increase in gradient on the Yakima and thus increased the rate of down cutting by the Yakima further enhancing the entrenched nature of the current river as well as the tributary Selah Creek. Possible changes on the Columbia River route through the Cascade Range may have been the result of volcanic activity.
Selah Creek Canyon and cliffs

Talus and strings of talus on the slopes north of Selah Creek

Another feature that can be seen are strings of talus on the slopes across the canyon from the rest area. These features are fairly common in eastern Washington. The features are thought to be formed primarily by summer cloud-burst rain events (Kaatz, 2001). These types of events are not common, but Kaatz suggested that they area a primary geomorphic process in eastern Washington that had been perhaps under appreciated.   


3 comments:

Elizabeth said...

Awesome!

Sam Crawford said...

When we've stopped there Sherri gets paranoid about the triangular yellow 'watch for rattlesnakes' signs.

The viewpoint up on the hill just southeast of Ellensburg (looking north) is great too.

Five Acre Geographic said...

Very nice narrative, Dan. Whether it's catching a seasonal view of Erigeron basalticus in bloom or appreciating the geological forces in evidence at the site, it's a great place. I'm sure Marty Kaatz appreciates the citation, too :-).