CASPER, WY (KTRK) -- The only cub of one of America's most famous grizzly bears is dead after a driver slammed into the baby and then took off.
The cub was known as Snowy, because of his blonde face.
VIDEO: Mother bear carries cubs across road
Police say a driver on U.S. Highway 89 struck and killed the bear cub Sunday night.
The bear's mother, known as '399,' pulled the cub off the roadway and over by a tree, but it was too late.
VIDEO: Bear cools off in a pool as record heat sets in
A memorial is being setup where Snowy died, says nature photographer Deby Dixon, whose images of the cub and his mother have been seen thousands of times on YouTube.
Dixon says she doesn't know whether the driver knows they hit a bear cub.
"We don't know the story, and we never will," Dixon says. "Everyone is in tears. It's a big loss."
VIDEO: Large bear sprints through neighborhood