External radio-transmitters were placed on 18 muskellunge in Moose Lake and Black Lake, Sawyer County, Wisconsin. Movements of the transmitter-tagged muskellunge were monitored for 14 months, during both the open water season and through the ice. Black Lake is predominantly a muskellunge, largemouth bass, panfish lake with an area of 52 ha, while Moose Lake is predominantly a muskellunge and walleye lake with an area of676 ha. Peak movements and activities occurred in spring and fall when water temperatures were 4-l2°C. During the summer months tagged fish occupied waters less than 2 m in depth at temperatures of 24-27°C. Greatest average swimming velocity of muskellunge observed was 50.8 m/minute. During winter months a tagged fish moved out of waters with low oxygen levels in the north bay of Black Lake to areas with a more abundant supply of oxygen. The monthly home range size of the muskellunge varied from 0.2 to 2.7 ha in Black Lake and from 2.3 to 27.7 ha in Moose Lake. Four spawning areas were identified and spawning activities were observed. Muskellunge moved onto spawning grounds when water temperatures reached 8-l0°C and remained on spawning grounds until temperatures reached about l4°C. Spawning occurred at night in depths less than 1 mover muck/sand bottoms with much debris and dead vegetation. Spawning areas were also approximately 1.5°C warmer than adjacent waters
