The silver 1974 Airstream Sovereign sparkles in the sun. Inside, the simplicity of the décor—sleek Douglas fir flooring locally sourced from Aurora, Oregon, white vinyl cushions to match the walls, turquoise throw pillows—makes the small interior seem much larger than it is. Counter space doubles as a wet bar, with a refrigerator and two ice wells. The vibe is pure Mad Men. “If you can’t tell already, we’re kind of midcentury freaks,” says owner Shelby Wilson.

This is the Stolen Pony Lounge, opened to the public in January 2017 and available for hire by anyone with something to celebrate. Wilson says the name is meant to conjure something an unsuspecting child might find at a birthday party—a lavish delight you didn’t know you needed until you got it. A Bainbridge Island native with a background working weddings and festivals, Wilson found a gnarly old trailer on Craigslist and ripped out the kitchen, bedroom, and bathroom to create her own party space.

Wilson hauls the Stolen Pony Lounge behind what she calls her Brown Beast, a Ford pickup truck complete with horns between its headlights, delivering it all over the Willamette Valley and to Vancouver, Washington. So far, clients have used the space for office meetings, green rooms, photo shoots, and parties. Last summer, Stolen Pony hosted Beck and Iggy Pop, headlining artists of the Pabst Project music festival. The trailer seats 15 comfortably.

“Everyone brings their own nostalgia into the space,” says Wilson. “It’s a unique experience every time.”