Wheat Ridge Greenbelt (always free)

The Wheat Ridge Green Belt, also known as the Clear Creek Trail, is a beautiful place to hike, bike, or just play on the jungle gyms! It features a paved trail that runs along clear creek, beginning in Golden and traveling for miles to the east, not really sure where it ends. The best place to access the Greenbelt in my opinion is near the WalMart on Youngfield Street. They usually have maps available at that trailhead. As you bike your way through the Greenbelt, you will encounter park after park where you can stop, have lunch, or play on the swings.

Location:
The Wheat Ridge Greenbelt and associated trail systems begin in Golden and travel all the way into downtown Denver, as well as branching off into the suburbs. There is park after park along the way where you can stop and go for a walk or unload your bike. If this is your first time on the greenbelt, you might want to start at the trailhead located on Youngfield Street near the WalMart. Just drive along Youngfield until you see the brown park signs near the log cabin. 

Youngfield trailhead location: Youngfield Street near 44th Avenue 

The AmericanTrails.org site gives some more details on the Wheat Ridge Greenbelt: