The saloon interior was designed by Harper Goff, who also designed for Disneyland including the interior of the Golden Horseshoe Saloon, which explains why they look so similar.
In a TV interview decades later, Doris Day humorously recounted the experience of watching the "rushes" from the first day of shooting on this film, when she had mastered the gestures and physical manner to play Calamity, but had not yet figured out the character's voice. She said she had to laugh at herself, "galumphing around in buckskin and being all gruff - but with a high, squeaky voice, sounding like Minnie Mouse!" She immediately realized she needed to bring her voice down to a lower register, and her character was then complete.
Doris Day had to lower the sound of her natural voice in order to sound more gruff to play the rough and ready Calamity.