Well actually it is a creek, Whychus Creek.
If you l closely in the distance there is a walk across bridge there.
Look even closer and there are some people splashing about in the cold waters.
This is all snow melt run off from the Three Sisters volcano mounts nearby.
The water thus is pretty cold.
Here is where the abandoned car was. I bet Andrew never returned and his Ford Explorer was towed.
Broken glass was on the ground where the rear window was.
The red car from New Jersey at the other location soon disappeared after I made that post.
In that case I imagine Kevin returned and fixed his car.