Is this Eris militaris or Pelegrina proterva? Or something else?
I think you are correct that this Salticidae or Jumper is a White cheeked Jumper from the genus Pelegrina. I can’t be certain of species but your id of Common white cheeked Jumper or Pelegrina proterva doesn’t seem far off. I don’t see a lot of observations of this exact species in Wyoming but it’s Wyoming right. Not in a bad way in a good way and it’s a definite possibility you have that exact species. It’s definitely White cheeked genus Pelegrina. Awesome Jumper I want to find one!!