Video from the park shows a pair of grizzly bear cubs wrestling on the road as two other cubs played nearby.
The man who took the video says he believes the cubs are offspring of one of the oldest known grizzlies living outside a zoo, Grizzly 399.
Social media famous Grizzly 399 is 24 years old and lives in the Grand Teton National Park and Bridger-Teton National Forest area.
According to The Guardian, Grizzly 399 was spotted with her four cubs for the first time in May.
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