Spearfish Creek is on fire right now! There's no reason to go anywhere else, really. Fishing in town and in the canyon is great and a variety of presentations can be utilized to catch fish. Terrestrials and dries are a great place to start. Work with a dropper (or even two) to get a few extra hookups. Beetles, ants, hoppers, and caddis (hint: size 18 caddis) will be your best bet. Morning and evening, even if you don't see caddis coming off the water, give it a try. The big ones are looking up right now. Droppers should be small...hot spot PT's, stone fly nymphs, and midge larva.
Whitewood creek is a great place to go when the rain hasn't been falling. Nymphs and streamers are your best bet here. Midges might be active in the evening, with the occasional baetis flying around on cloudy days. Mostly under-surface activity here.
If you want to get in on more dry fly stuff, go to crow creek. Super clear water, picky fish, and a lot of vegetation, but you will be a better angler because of it.
Rapid Creek is fishing better now that the water is to somewhat normal levels. Nymphs are still catching the most fish, but streamers are always a good bet for enticing a big one from out behind a boulder or under a bank. Terrestrials will start bringing some fish to the surface, but you'll always want to have a dropper with a smaller profile nymph setup. Tricos are going early, so fish them if you see risers.
Fishing will only get better as autumn approaches. With school getting started, there are fewer crowds to content with. Get out and catch some fish while the weather is awesome!
Tight lines and good fishing from all of us at Spearfish Creek Fly Shop