Rattlesnake Mountain, a popular outdoor recreation resource of the metropolitan Hartford area, is known for its cliff-top scenic vistas, unique microclimate ecosystems, and rare plant communities.

[2][3][4] Roughly 1 mile (1.6 km) in diameter, Rattlesnake Mountain rises steeply 500 feet (150 m) above the Farmington River valley to the west.

The south side of the mountain supports the headwaters of the Quinnipiac River, which flows directly into Long Island Sound.

Subsequent faulting and earthquake activity tilted the strata, creating the cliffs and ridgeline of Rattlesnake Mountain.

Hot, dry upper slopes, cool, moist ravines, and mineral-rich ledges of basalt talus produce a combination of microclimate ecosystems on the mountain that support plant and animal species uncommon in greater Connecticut.

[3][6] Will Warren's Den, a boulder cave located on the west side of the mountain, is a historic landmark of the town of Farmington.