Peak Mountain is known for its expansive views from 200 feet (61 m) high cliffs overlooking the historic Old Newgate Prison, Congamond Lake, and the Salmon Brook Valley of north-central Connecticut.

The mountain formed near the end of the Triassic Period with the rifting apart of the North American continent from Africa and Eurasia.

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

The East Granby Land Trust has played an active part in the conservation of Peak Mountain and its viewshed.