Expect smoky skies. Watch out for all the fire TFRs, particularly if you head west to check out the coast. It is one of the worst years on record for fires in Oregon. There are other fire TFRs throughout the west; that happens every summer.
Hopefully they'll have them somewhat better controlled by then (they can linger on till winter, though,) but the only two times I was up in the last couple weeks up near Eugene it was pretty hazy even there. I would expect it is much worse in Klamath Falls area. It didn't look too bad in eastern Oregon.
To give you an idea of some of the haze, I took the first attached picture yesterday at 8500 ft, looking north from somewhere close to Crescent Lake, 5S2. At the time KEUG reported ceilings at 15,000 ft. You can just barely make out the snowy Sisters peaks, only about 35 miles away. (I was returning to home to Creswell, 77S, from Christmas Valley, 62S. Just for the heck of it.) On a decent day Mount Hood, about 110 miles away, would be visible.
Only caution is to make sure to take photos (and videos, if equipped) and post some here, lest yee be ostracized. Aviate, navigate, communicate, take pictures. For instance, I saw the interesting formation in the second attached photo and it wasn't till I looked it up when I got back home that I discovered it was the main attraction of Fort Rock State Park, Oregon.
