Rhododendron State Park is named after the 16-acre grove of Rhododendron Maximum, which is the focal point of the park. A 0.6 mile-long universally accessible trail encircles the grove allowing visitors to observe, close up, the fragrant clusters of pink blossoms as they burst into bloom in mid-July.

A wildflower trail, maintained by the Fitzwilliam Garden Club, winds through the forest adjacent to the grove. From early spring to the first frost, wildflowers bloom throughout the 2,723-acre park. The last blooms in the fall are complemented by the forest's brilliant foliage. Visitors exploring the trails are often serenaded by song birds which live in the grove.

The rhododendron grove, which is the largest in northern New England, was designated a National Natural Landmark in 1982.