A 56-year-old woman was killed when she was thrown from her motorcycle trike on the Yucca Grade Sunday evening. According to the California Highway Patrol, Catherine Matthews was riding a Harley-Davidson Freewheeler Trike eastbound in the number 2 lane on Highway 62 about 60 miles per hour, just east of Yucca Park Road in Morongo Valley about 8:18 p.m. A green Mitsubishi Montero, being driven by Galo Zurita, 41, of Yucca Valley, was ahead of the trike at about 45 miles per hour. For unknown reasons, Matthews drove her trike into the rear of the Montero in front of her. The collision threw her from the bike and she landed on the highway. After the collision, Denise Gilpin, 63, of Yucca Valley, was driving a Ford F-500 eastbound on the highway at about 55 mph. Gilpin collided with debris from the initial collision. Catherine Matthews, who was wearing a helmet, was taken by Morongo Basin Ambulance to Desert Regional Medical Center with major injuries, where she later died. Galo Zurita, and his passengers, Russell Scaduto, 68, of Morongo Valley, and a 5-year-old girl from Yucca Valley, as well as Denise Gilpin in the Ford, were not injured. The CHP says alcohol or drug impairment may be a factor in the crash. Anyone who witnessed the crash should call CHP Officer Puentes at 760-366-3707.