Week 3 - Columbia River - David Clark

After last weeks adventure down south, to Joshua Tree, I wanted to visit a landmark a little closer to home. Being in quarantine still, a quick hop down south is just what the Dr. ordered (not literally of course). The Columbia River is just to my south, about 60 miles. When you hit the Columbia, you can go east following the river on highway 14 to visit the beautiful Columbia River Gorge. This is where I went, and for this trip I brought along my dog, Bo.

As Bo began to sniff around, he looked at the river with delight in his eyes, he wanted to go for a swim! I told him to hold on, the river looks beautiful and refreshing, but may not be a good river for swimming. He looked back at me, wondering why I was holding his leash so tight. "Let me explain bud." I told him. "Because this is the only river that cuts through the Cascade mountains, it is the only source for the drainage basins east of the mountains." "Also, because it is cutting a path through the mountains, the type of channel is a bedrock channel." Bo looked back, still not understanding. "This means that the water velocity and discharge is very high, it is moving fast!" He was still not impressed, certain his strong Mastiff limbs would proper him through the water. "Why do you think they built all those dams on the river Bo? High velocity makes for an excellent dam." "In fact, in the past glaciers used to dam the river naturally, creating ice dams."

He begrudgingly accepted my explanation, and we sat down to watch the river a bit. "See how clean the water is bud?" I asked. "This is because the river bed is so hard. The river cannot pick up fine sediment and transport it as bed load." "Instead, the river uses quarrying, abrasion, and corrosion over long periods of time. The lack of loose sediment is why the river is so clear! You could say the river has very high capacity and competence." "See how high the valley walls are? That is because the river has been down cutting for millions of years!" "See those level spots on the valley walls? Those are called terraces, where the river once ran". Bo licked his paw, which he then used to scratch his jowels. "Agreed bud, very impressive!"

We hopped back into the car, and started headed back west, toward I5 which goes north. As we hit I5, I explained to Bo that down further is where the Columbia dumps into the Pacific ocean. "Think of it bud, this is where all sediment deposition happens!" "You see how the river slows down? This is because it's velocity is slowing as it hits the Pacific." Bo looked at me, obviously wanted to know about the drainage patterns. "Good question bud, the Columbia spreads out into a dendritic pattern, with little inlets near Ilwaco and Long Beach." As we headed north on I5, Bo and I were silent, daydreaming about gradient levels and discharge.