Roger, you are giving me flashbacks with this posting. The Army graciously provided me with several all expense paid trips to the Yakima Firing Range while I was stationed at Fort Lewis, Washington. All I can remember of that place is extreme heat, snakes, and a very dusty and dry desert floor. We went out there the summer following the blast at Mt. St. Helens and there was about 4-6 inches of pulverized ash on the ground. We had to wear surgical masks the entire time (that was when we weren't wearing gas masks, which is worse) in order to protect our lungs from the acidic ash. What a garden spot!! The upside is that if you are crazy enough to go out there you will probably be hiking alone.
It does look pretty from the photo you have provided. Perhaps it is all different when you are not sucking it up digging and refilling foxholes for three to four weeks at a time in the summer heat.