Im assuming you mean from Bridgeville down through the gorge. Temps get too high or can get too high ibln June so watch the temps. Dennis at Catskill flies put up daily reports on the river.
I've got 2 buddies that fish it regularly. He has hooked some very, very big fish. He's hooked what we assume is the same fish twice in 3 weeks. Same pool twice on 3x fluoro and got busted off both times.
4wd to access spots, water, flashlight, camera and let people know where you are. If you hike in a long way and break an ankle, nobody will find you for days or longer. Being in good physical shape is also necessary. Expect to see bears, rattlers and possibly a bobcat prowling the edges if you are quiet.
If I'm not mistaken, it also gets some decent caddis hatches, sulphurs and ISO hatches. You like rough country, miles of pocket water, solitude, opportunity for some unexpected BIG fish? It's all there for your use. Some sections contain leg breaking chunk rock wading. Not for the faint of heart.