Colorado mayors will help advance a nationwide mission to put a high-quality park within a 10-minute walk of every American.

The Trust for Public Land, National Recreation and Park Association and Urban Land Institute will launch the nationwide campaign in 2018.

The JPB Foundation has donated almost $3.5 million for project.

The initiative includes working with some cities on ways to measure policies and strategies to locate a park with a half-mile of everyone, which could prove a costly challenge.

The Trust for Public Land said research indicates more than 100 million Americans don’t have access to parks in that proximity now.

“Reaching 100 percent served in cities nationwide will require major advances in park finance and construction; zoning changes to encourage park development; embedding this goal into city parks master plans; the expansion of ‘joint use’ agreements that open school playgrounds, tracks, and gyms for public use after hours and on weekends; and other innovations,” the partnership said in a statement.

It’s got the endorsement of 134 mayors, including seven from Colorado. In addition to Hancock the campaign is endorsed by Steve Hogan of Aurora, John Suthers of Colorado Springs, Wade Troxell of Fort Collins, Marjorie Sloan of Golden, Heidi Williams of Thornton and Herb Atchison of Westminster.

“In Denver, we know great cities need great parks,” Hancock said in a statement. “It’s never been more important to protect, preserve and grow our parks and recreational opportunities, especially as our city grows. I’m proud to join this campaign with mayors across the country.”

Colorado Gov. John Hickenlooper cites the 10-minute goal among his highest priorities for the state before he leaves office in January 2019.

His Colorado the Beautiful program features an interactive database that maps more than 39,000 miles of trails across the state, and put that information online.

Hickenlooper said Colorado can meet the 10-minute goal within a generation.