There are plenty of great spot to fish in Southern Utah. The best, most current information regarding licensing, the conditions for reservoirs, lakes, and rivers can be found on the Utah Division of Wildlife Resources website. They also have a downloadable fishing guide FREE for the regions of Utah State.
Great place for large mouth bass and rainbow trout. The bass is typically found on the west and north shorelines.
Sand Hollow Reservoir:
This is the place for you especially if you like large mouth bass. Bluegills seem to have disappeared.
Bass are looking strong on the west bank. Fishing is even better with a boat. All boats now have to be treated for quagga mussels.
Some other good spots to fish include: Sandove Reservoirs, Baker Reservoir (huge brown trout), Enterprise Reservoir (upper large rainbows), and Otter Creek Reservoir