Madison Boulder Natural Area
473 Boulder Rd
Madison, NH 03849
Madison Boulder Natural Area is home to the largest known glacial erratic in North America, and among the largest in the world. Madison Boulder is a huge granite rock measuring 83 feet in length, 23 feet in height above the ground, 37 feet in width, and weighs upwards of 5,000 tons! The 17-acre site was acquired by the state of N.H. in 1946. In 1970 Madison Boulder was designated a National Natural Landmark by the U.S. Department of the Interior because the enormous erratic, "is an outstanding illustration of the power of an ice sheet to pluck out very large blocks of fractured bedrock and move them substantial distances." Recent work puts the boulder's age at around 14,000 years old.
This park is always open for recreation unless closed or restricted by posting. During the off-season the park is typically not staffed and comfort stations are not available.
The off-season poses unique risks inherent when participating in outdoor recreational activities. Please be aware that many State Park areas and trails are not staffed during the off-season, and day-use fees are not collected. Recreationists should possess the necessary knowledge, skill, and equipment to ensure their own safety. Users assume all risk while recreating in State Park lands.
Are pets allowed at Madison Boulder Natural Area?
Pets are permitted in the park. See the NH State Parks Pets Policy for more information.
Keep Your Parks Clean
Through the Carry-In/Carry-Out Program, you can help us keep your parks clean and beautiful by carrying out whatever you carry in. Thank you for your cooperation and remember to recycle.
Access for Persons with Disabilities
Please contact the park office directly for information regarding disability access needs.