Ice fishing is winding down. High elevation waters still have safe ice but will start getting slush on top of ice and so conditions will become unpleasant.
Walleye are starting to draw attention. Fishing is slow now (Feb 29) but will pick up by mid-March. Fish the pre-spawn for good action at Willard Bay, Utah Lake, Deer Creek and Starvation. We have great articles telling how to catch walleye in Utah.
Fly fishing is becoming good on streams, as snow melts and access improves. Our major fly fishing waters all have accessible spots offering good action. They include they Green, Provo, Weber and Ogden rivers. As the weather warms, streams will pick up runoff. As that happens, fish the tailwaters protected by dams. See our excellent article on fishing the Green during spring.
Trout fishing will also pick up in lakes and reservoirs. The Utah side of Flaming Gorge has open water and usually fishes very well on warm spring days. Otter Creek should be ice free any day now and will be good. Deer Creek has been open all winter and people report good action. Jordanells has had some ice but will be completely ice-free about now with good fishing.
Me? I'll put my boat on the Colorado at Lees Ferry during mid-March. The big river offers exellent action for big rainbow trout. It fishes well year-round and it particularly good in spring.
Hiking and backpacking will be great in many southern Utah areas. March and April are excellent times to backpack Grand Gulch, Coyote Gulch, Dark Canyon and such places. I'll be hunting Anasazi ruins on Cedar Mesa during late March.