A 60-year-old Spokane Valley woman has died in an ATV accident on Rathdrum Mountain. Sandy Birch was traversing a steep slope when the ATV she was driving overturned, according to the Kootenai County Sheriff’s Office. Deputies responded to an area near the top of the mountain at 3:20 p.m. today. Initial reports indicated the woman was injured and that CPR was being performed. However, she died at the scene. Birch was not wearing a helmet, police said. Rathdrum Mountain is located west of the city of Rathdrum. Much of the land is privately owned, although lumber companies do allow public access, according to the Friends of Rathdrum Mountain Web site.