The airplane was taking off. As the pilot began his takeoff roll, he noticed the airplane sliding just a little. As he continued to accelerate, he got the airplane straight and proceeded down the center of the runway. The pilot said that at about 75 knots, he rotated. He said he was watching a snow plow that was farther down the runway and off to the side. He'd just gotten into the air, approximately 5 feet above the runway, when the airplane drifted left and the left main landing gear caught a snow bank. The airplane came down, impacting the ground off the side of the runway and coming to rest in the snow. The pilot and the four passengers on board were not injured. The airplane sustained substantial damage. The pilot said he felt he did not put in enough right rudder to counter the torque of the propeller after he left the ground.