DORSET, Vt. (AP) – There is a new gate protecting the entrance to Dorset Cave on Mount Aeolus, the highest known cave in New England where up to 20,000 bats are known to spend the winter.

The $16,625 iron gate across the mouth of the cave is designed to keep people out and protect the state’s most precious bat habitat inside the limestone cave.

Several species of bats – including the rare Indiana bat and the state-endangered small-footed bat – are here after completing an annual migration to the high-elevation cave this month.

“This is a spectacular place,” said Jim Hand of Manchester Center, who volunteered to help haul the 5,000 pounds of iron used for the gate. “A lot of people never see it like this. They walk by the entrance and know there’s a cave here, but they walk by at the wrong time of day or they don’t pay attention to the creatures that are in here. These nighttime visits are really something.”

Dorset Cave, high above Manchester, is the largest hibernaculum – a place where bats hibernate for the winter – in New England.

The wintering bats spent the summer feeding on beetles, moths and mosquitoes in states including Vermont, Maine, Massachusetts and New York. The U.S. Fish and Wildlife Service helped pay for the gate to ensure no humans enter the cave and bother the hibernating bats.

“This is critical habitat for some of our state’s important and often overlooked wildlife,” said Rose Paul of the Vermont chapter of The Nature Conservancy, the nonprofit environmental group that owns the Dorset Cave land. The Conservancy spearheaded this month’s construction project of the gate across the cave’s mouth.

The gate closes off Dorset Cave, often explored by intrepid hikers or cavers, from Sept. 1 to June 1. People are allowed to explore its guano-covered floor in the summer. A gate was built 19 years ago, but rebuilt this year to be more human-proof and bat-friendly.