Ada County is about 50 days from opening a park unlike anything else in the Treasure Valley.

The Park at Expo Idaho is roughly 50 acres along the Boise River in Garden City, next to Athletic Club Boise Stadium, on the site of the old Les Bois horse track. Ribbon cutting is Friday, Oct. 23, 2026.

KTVB’s Justin Core walked the site as crews put on final touches. The backbone of the project is not the playground or the skate park. It is putting the land back to what it was before the racetrack.

About 19 acres are wetland restoration. Crews have put in more than a million native plugs, 94 species, grown at 16 nurseries across the Northwest. Irrigation is temporary: 390 zones to get plants established, then nature takes over, the way it does along the Boise River a few feet away.

Mink, beavers, frogs, dragonflies, and hummingbirds are already on site. County staff call it ecological uplift. On day one, they say, you will see it.

The recreation is built into that landscape. California Skateparks, the team behind the 2024 Paris Olympics venue, designed a world-class all-wheel skate garden meant to feel like skating through nature, not at the edge of a parking lot. The nature playground includes one of the largest swing sets in the United States. There will be more than three miles of trails, a roller derby rink, a food-truck plaza off the Greenbelt, and bike parking so soccer crowds can ride instead of drive.

The project is funded in part by federal American Rescue Plan Act money awarded to Ada County. Officials say everything had to line up: the 50 acres, the type of land, and that federal funding. Without it, they say, a park like this would have taken tens of millions in private money.

Oct. 23 is the ribbon cutting, and the day the plantings will look the worst. The county’s pitch is that the park gets better with time, next year, in five years, and for the next century.

Video: KTVB, “Take a tour of the Park at Expo Idaho ahead of grand opening.”
Renderings courtesy PORT Urbanism, Marlon Blackwell Architects, and Ada County.