About Rocky Hill

View of beaver pond and heron rookery at Rocky Hill

Located on the Groton-Ayer town line, Rocky Hill Wildlife Sanctuary is a land of impressive ledges, large boulders, beaver ponds, vernal pools, and extensive uninterrupted woodlands.

The sanctuary lies within a state-designated Area of Critical Environmental Concern and supports moose, beavers, and porcupines, as well as nearly 100 species of birds and more than 240 plant species.



Trail Mileage

3 miles
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Sanctuary Highlights

  • Rocky outcrop that overlooks a beaver pond provides a unique, eye-level view of numerous active Great Blue Heron nests.
  • Granitic ridges, with exposed ledges on the hillsides and smaller outcrops and large boulders that provide protective cover for porcupines, nesting Turkey Vultures, and snakes.
  • Plenty of rock surfaces, ideal growing sites for lichen, such as rock tripe or for rock polypody fern.
  • Wood Frogs in the vernal pool alongside the Vernal Pool Trail in spring.


Cardinal Lane, Groton, MA 
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Hours & Admission

Trails: Daily, dawn to dusk
Free, donations appreciated

Property Regulations

All of the land at our wildlife sanctuaries is protected. By conserving these open spaces, Mass Audubon, along with our members and partners, is able to fulfill its mission of protecting the nature of Massachusetts.  

  • No dog walking or horseback riding; please leave all animals and pets at home (service animals welcome
  • No walking off trail  
  • No collecting or picking natural items.  
  • No bike riding or operating motorized vehicles; day passes are available for powered mobility devices   
  • No running, swimming, or camping 
  • No operating drones or other remote-controlled vehicles   
  • No fishing, hunting, trapping, or releasing of animals   
  • No feeding wildlife   
  • No smoking