Rent a boat or pontoon for a few hours on the multiple lakes nearby
https://blog.winterparkresort.com/top-10-fall-must-dos-winter-park/
https://www.alltrails.com/us/colorado/granby
https://www.mtbproject.com/directory/8012339/granby
https://www.visitgrandcounty.com/hot-sulphur-springs/