Madison Boulder

erratic, New Hampshire, United States

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Last updated

June 30, 2026

Quick Summary

An erratic is a rock fragment, often a boulder, that has been transported by glaciers from its original location to a different area. These transported rocks differ from the local bedrock and can range in size from pebbles to massive boulders weighing thousands of tons.12

The Madison Boulder in New Hampshire is an example of an erratic. It is a large glacial boulder that was carried by glaciers far from its original source. Studies of erratics help scientists understand the direction of glacial movement and the extent of past ice ages.31

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Carroll
A landmark is the Madison Boulder, one of the largest granite glacial erratics, measuring 83 feet (25 metres) tall and 37 feet (11 metres) wide. The county is largely forested with pine, maple, and birch, except for large stands of spruce and fir in the northwest. Carroll county contains…
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A landmark is the Madison Boulder, one of the largest granite glacial erratics, measuring 83 feet (25 metres) tall and 37 feet (11 metres) wide. The county is largely forested with pine, maple, and birch, except for large stands of spruce and fir in the northwest. Carroll county contains…
Read More