Justin's friend owns a "very fancy estate" and for the past two weeks neighbors have noted a suspicious stage being constructed over the ranch.
Spies told Janet Charlton's Hollywood the couple held a rehearsal dinner on Friday and the official ceremony on Saturday, with friends of the famous duo staying at the nearby Four Seasons Hotel.
Celebrity wedding cake designer, Sylvia Weinstock (she's baked for Billy Joel, Catherine Zeta Jones and Ivanka Trump), tweeted on Saturday that Jackson Hole was a "marvel" which, of course, led to speculation that she'd designed a confection for Justin and Jessica, too.
A Jackson Hole wedding would make sense as it was same place Justin reportedly popped the question during a snowboarding trip over the holidays, and one of the duo's favorite places to vacation.
Jess, for her part, has admitted on various occasions that she's not much of a "detail-oriented" planner and told several news sources she hadn't thought much about her upcoming nuptials.
Well, except to make sure that a certain bubbly, blond ex of her fiance's wasn't present.
"Jess considers Cam her love rival," a pal of the couple tells Star. "It burns her up that Justin has stayed friends with Cam after breaking up. When they were going over the invite list, Jess crossed Cam off and told Justin, 'That woman's not coming to my wedding!'"
Mazel tov, Justin and Jessica!