Subscribe | UPI Odd Newsletter Subscribe GARDINER , Mont., May 11 (UPI) -- A group of tourists visiting Yellowstone National Park near Gardiner, Mont., have learned firsthand not upset a mama bear. Montana Fish, Wildlife and Parks has released video of a black bear chasing a group of Yellowstone visitors away from her three 13-month-old cubs. Advertisement "It serves as a reminder that wildlife can be unpredictable," the agency said in a Facebook post. "For your safety and theirs, respect wildlife and give them room to roam." Bob Gibson, the agency's communication and education program manager, told NBC News that the tourists were "absolutely in danger." Gibson said the mother would have been more protective of her cubs if they were younger. The National Park Service warns visitors to stay away from bears, especially bears and their cubs. Read More Sun bear attempts escape from Japanese zoo enclosure Florida family raising 13 bears in their back yard California man, 73, punches 300-pound bear to defend his dog