I WAS DRIVING ON A SECONDARY ROAD AT APPROXIMATELY 35 - 40 MPH AND AS I CAME TO THE CREST OF A DOWNHILL SECTION, I LIGHTLY TOUCHED THE BRAKES DUE TO SNOW ON THE ROAD. THE TRUCK VEERED VIOLENTLY TO THE LEFT AND WENT INTO A SKID. I CORRECTED AND AGAIN LIGHTLY TOUCHED THE BRAKES AND THE TRUCK AGAIN VEERED VIOLENTLY TO THE LEFT AND I WAS UNABLE TO CORRECT BEFORE THE TRUCK LEFT THE ROADWAY AND STRUCK A LARGE TREE STUMP. THE TRUCK IS AWAITING INSURANCE ADJUSTMENT DECISION ON REPAIR.*AK