We caught it last year at 1000+ in June, if i remember right, and saw one group at the put-in. What I'm remembering right now is that we didn't see another group the whole trip. Put in above Slickrock and took out at Moab 5 days later, Monday to Friday. Wait, we actually did pass one group of boy scouts, but I think that's it. The launch points we passed looked pretty desolate to me, and most of them on dirt roads, but if it runs longer this year, it's probably true that there will be more groups launching/ending with you. Good luck and have fun!