Cherry Creek State Park

Cherry Creek State Park technically sits in Aurora, but the practical geography is north DougCo's: from Lone Tree you're inside the gates in 10 minutes, from Highlands Ranch in 15, from Castle Rock in 25. The park covers 4,000 acres around an 880-acre reservoir built in 1950 for flood control, and it does enough things well that almost every category of weekend outdoor person has a reason to come: 35 miles of multi-use trails (15 miles paved, the rest dirt), a swim beach, three boat ramps, an archery range, a model airplane field, a shooting range, a horse rental concession, and the largest off-leash dog area in the metro at 107 acres.

Fees are $11 per vehicle per day or $83 for the annual Colorado State Parks pass, which pays for itself in eight visits and gets you into Chatfield, Castlewood Canyon, and Roxborough on the same pass. The 4.75-mile paved Cherry Creek Trail loop around the reservoir is the most-used route and the right answer for a casual ride or run with kids; the dirt singletrack on the east side is where DougCo mountain bikers actually train. Sunsets here are a real argument for the $83 pass; the west-facing reservoir views with the Front Range silhouette are some of the best in the south metro.

The honest negatives: summer weekend lines at the entrance can hit 30 minutes, the swim beach gets crowded enough that DougCo families often drive to Chatfield instead, and water-quality advisories happen every year or two during late-summer algae blooms.