On Wednesday, June 18th we hit the road in just the truck – leaving our home (the trailer) at Casey's Riverside RV in Westfir, OR. We had wanted to take a quick look around Bend, OR and also the beautiful mountains, lakes and streams of the Cascades.
We drove southeast up the conifer studded mountainous Hwy 58 toward Willamette Pass, the summit at 5128'. Just before the pass we came to a geologically fantastic waterfall at Salt Creek. We had read and heard that we should stop in to see the falls, but had no idea how exhilarating it would be. As we drove further into the Cascades, after visiting the falls, we came to understand that nearly all of the area was formed by,and much of it still covered in exposed lava rock.
Here is how this spectacular waterfall was formed: About 4 million years ago the Cascades began their uplift. Moisture laden winds from the Pacific Ocean dropped abundant moister on the landscape. Running water sculpted the land into V shaped canyons.
During the ice ages, the creek was turned into a thick ice river which further sculpted the V canyon into a deeper U shaped canyon.
Later, intense volcanic activity allowed basaltic lave to flow into the U canyons. Over time the impact of successive glaciations on the weaker pyroclastic rocks under the basaltic lava rock caused the basalt to break off in chunks, forming steep cliffs.
Continuous erosion of the underlying layer of rock resulted in this particular type of waterfall which is called a “plunge basin”.
As mentioned above, this area is covered with lava flows. It's like walking through sections of Hawaii....or through Craters of the Moon in Idaho. Many gorgeous mountain peaks were formed during this geologic period – some of the peaks being dormant volcanoes, and others the result of uplift. Diamond Peak was prominent in this first section of our drive to Bend up Hwy. 58.