GRAND CANYON NATIONAL PARK, Ariz. - Family members say one of hikers swept away while crossing a remote creek in Grand Canyon National Park is the wife of the founder of the Merrell Boot Company.

The uncle of the missing teen from Tennessee told The Associated Press that the boy, his mother and his stepgrandparents were crossing a water trail Saturday evening when he and his stepgrandmother fell in and were swept away by the water.

Mark McOmie identified the step-grandparents as Randy Merrill, founder of Merrell Boot Co., and his wife Lou-Ann.

The McCallie School in Chattanooga, Tennessee, released a statement Monday saying the missing hikers are eighth-grader Jackson Standefer and his stepgrandmother.

A helicopter and drone on Monday are helping searchers on the ground try to find the pair.