Fresno is 17% full with no inflow & about 40 cfs outflow. The reservoir is ice covered.
Nelson is 71% full with no in or outflow. The reservoir is ice covered with fish/spear houses being placed especially in bays & areas where ice will support them. If you fished & caught fish before the reservoir was ice covered, these would be the areas to start. Tip-ups with live minnows & one jigging set up would be my choices.
Be safe & good luck.