At about 1130 Mountain time the airplane sustained substantial damage following an off-airport precautionary landing attempt during an aerial application flight. The Private pilot and sole occupant sustained minor injuries. Visual conditions prevailed. The pilot subsequently reported that he was attempting to climb over a low ridge when the airplane encountered bad air and began to sink. The pilot stated he lowered the flaps and applied full power, however the airplane continued to sink and he elected to land the airplane in an effort to avoid approaching power lines. The airplane collided with terrain in a left-wing-low attitude, resulting in substantial damage.