Madison Boulder, New Hampshire - Considered to be one of the largest known glacial erratics in North America, Madison Boulder weighs roughly 4,662 tons. It is 87 feet long, 23 feet wide, and an impressive 37 feet high. It's worth mentioning that the size of the boulder ranges from source to source. If you enjoy the geology of New Hampshire, this boulder is worth a visit. It is massive!..[Continue reading] ...