A search was underway along the Colorado River in Grand Canyon National Park for a man and his dog who might have tried to float the river on a wooden raft/NPS HO

A search was underway Wednesday along the Colorado River in Grand Canyon National Park for a man and his dog who might be floating down the river on a makeshift wooden raft.

The park issued a missing person alert after a vehicle belonging to Thomas L. Robison of Santa Fe, New Mexico, was found Sunday abandoned at Lees Ferry within Glen Canyon National Recreation Area. The 58-year-old Robison "is believed to have attempted to travel down the Colorado River with his small dog on a wooden raft," the park release said.

Robison was described as a white male, 5-foot-10 in height and weighing 160 pounds with brown hair and hazel eyes. His dog was described as a 25-pound Welsh Corgi. A flyer alerting the public to the search contained a photo of a crude raft built from four planks.

Anyone who may have seen Thomas Robison was asked to contact Grand Canyon Dispatch at 928-638-7805.