What was the first appearance of Ranger Smith from Yogi Bear?

Ranger Smith's first appearance was in the 1961 Hanna-Barbera cartoon short "Yogi Bear". This short, featuring a picnic basket-loving bear in Jellystone Park, is considered the origin of both Yogi Bear and Ranger Smith.

While the short itself is just over 6 minutes long, it introduced both characters and established their dynamic, which would become a key element in the entire "Yogi Bear" franchise.