A clip of the sweet interaction, taken by the young girl's mother, Meagan Sawyer, was uploaded to YouTube. Ms Sawyer told WPDE that little Riley loves playing peek-a-boo with her eight-month-old sister and just started playing when she saw the animal.
Riley was "amazed" that the bear played along.
"He was like up against the glass, like in the middle. We were playing peek-a-boo...we went to the left, then the right, then the left, then the right," Riley told ABC15.
Reactions to the video, however, have been mixed.
"I know this should make me smile, but it makes me sad to see the bear caged," writes Jenny Li on Twitter.
"Lovely to see the innocence of a child reflected in a lonely animal," tweets Paul Thompson.
"Granted, zoos are not the ideal place for animals but they are a necessary evil…zoos may prove to be the difference between survival and extinction of a species," remarks Jason Mitch on YouTube.
Little Riley, though, can't wait to go back and see her new friend. "I want to play peek-a-boo with him again."
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