When I used to fish at Texoma for crappie we had good luck on the docks in 10-30' of water in the winter, and usually around the first of April a few males would move up to spawn, full swing spawn was usually around that late April early May time. Remember Texoma is a huge lake, and warms up a whole lot slower than the rest of the lake around here. The west end heats up faster too with murkier and shallower water, I've caught spawning fish as late early June out there. I always liked to fish the jig and bobber bite in the coves when the spawn started to heat up.
TCU class of 2019