I play in St. George, find the Facebook group "St. George Slowpitch +" You'll have better luck finding a team there.
Or, worst case do what I did and show up opening day and look for a team playing short.
Fall 1 pitch starts the last week of October, followed by the Halloween tournament.
Also, looks like St. George now how a Free Agent signup.
https://www.sgcity.org/sportsandrecreation/allartsandrecreation/softball