NEWBURY, N.H. (AP) – The U.S. Fish and Wildlife Service is offering to swap a piece of land in Errol for the former summer home of John Hay.

Hay was President Lincoln’s personal secretary and the secretary of state under presidents William McKinley and Theodore Roosevelt.

The 164-acre John Hay National Wildlife Refuge is on Lake Sunapee in Newbury and was donated to the federal government 20 years ago as a historic site and sanctuary for migratory birds.

The part with the buildings and gardens is known as the Fells and has been maintained for 10 years by the volunteer Friends of John Hay Refuge.

The arrangement has challenged both groups. The Fish and Wildlife Service is charged with managing wildlife habitat, not historic buildings. Many of its rules clash with the volunteer group’s goals. Meanwhile, the volunteer group has struggled to raise money and make long-term investments in the property because it fears it could lose access at any time.

“They’ve allowed something that really wouldn’t be typical at a refuge,” said Karen Zurheide, the executive director for the volunteer group. “But it’s not tenable forever. It’s really time to fix it and formally recognize that the site and the public are served by a different arrangement.”

The two groups have been quietly discussing a solution for years. The land swap idea was suggested last summer and Fish and Wildlife began searching for a suitable replacement property.

Federal law precludes the service from selling its land outright, but it can trade the Fells for a similarly priced parcel with equal or greater ecological value.

Here’s how the swap would work: The New Hampshire Audubon Society would buy a 727-acre property in Errol abutting the Lake Umbagog National Wildlife Refuge. The government would swap the northern half of the Hay property containing the summer home for the Errol property. The volunteer group would buy the Hay parcel from the Audubon Society and agree to maintain it.

The Errol parcel’s road frontage on Route 26 makes it attractive to the Fish and Wildlife Service because of its potential for residential development and because it will expand public access to the refuge.

The refuge spans the New Hampshire-Maine border and includes wetlands and woodlands for interior forest nesting birds, including ospreys, black dugs and bald eagles.

Paul Casey, who manages the refuge, said the Errol parcel is one the Fish and Wildlife Service has been eyeing for some time.

“Naturally this piece is a piece of the puzzle that fits nicely,” he said.

Meanwhile, the volunteers have secured about $750,000 in pledges from 400 donors, enough to cover the purchase price of the Errol lot, legal fees and contingency costs. It hopes to continue raising money to endow its future management of the Fells.

“We’re very encouraged,” said Nick Mitchell, the chairman of the group’s board of directors. “The support we’ve received from the communities is beyond our expectations.”

If the deal goes through, the group plans to add signs, build a better parking lot, rehabilitate a lakeside cabin and make other investments in the infrastructure, but not change the way the property is managed, said Zurheide.

The southern half of the Hay property would remain under federal ownership. Federal officials plan to develop a wheelchair accessible wildlife trail.

Before the deal can be completed, the public must be given time to comment.