We ran the Encampment in 2007 and I remember the road being closed even towards the end of May. You can check with the Forest Service. Although the typical road was closed, a local fishing guide service ran our shuttle (which was pretty long) and knew another way to the put-in and didn't charge too much. He dropped us directly at the put-in.
That run was really incredible. Nothing too tough except the one big hole on the only class V rapid. It was probably a class V- move to avoid subbing out in the hole. The runnout to that rapid goes on and on for at least a mile of class IV and IV+ so a swim would be brutal and quite cold. If we had more time, camping in there would have been beautiful, but the run goes by pretty quickly.
I remember that we had to be pretty heads up when approaching the big rapid with wood issues above the entrance (which may be non-existant now). Know where that rapid is because someone died there a couple years ago because they started to float into the rapid and pulled into a last-chance eddy, flopped over a rock and pinned under water.