BOZEMAN - The Gallatin County Sheriff's Office is asking for the public's assistance in locating 63-year-old David Butzin.Butzin was last seen on Nov. 10 and was reported missing on Nov. 25.According to authorities, it is common for Butzin to have little contact with family or friends for extended periods. He has been known to hike without notifying his family or friends of his whereabouts and enjoys adventuring off-trail.Butzin's vehicle was located Tuesday, Nov. 26 at the New World Gulch/Bear Canyon area. The Gallatin County Sheriff's Office Search and Rescue continues to search that area.If you have any information regarding Butzin's whereabouts contact Gallatin County Communications at (406) 582-2100.