By all accounts, everybody loved the experimental National Park Service visitor center at Arcola Mills, considered the oldest lumber mill site in Minnesota.

Thousands of people came over three short seasons when about 50 volunteers staffed the 1847 mansion as an interpretive center. Ranger Jonathan Moore said visitors raved at the beauty of the wooded land on the St. Croix River, where a village once surrounded a water-powered sawmill.

"Of the 13,000 people who had been there in the past three seasons, 12,500 had never set foot on the place," said Moore, the ranger working to establish a permanent visitor center on the Minnesota side of the St. Croix River.

But this month, the once-blushing relationship between the park service and Arcola Mills dissolved into a dispute over money, apparently ending any hope of a lasting partnership. Even plans to continue the visitor center until Oct. 21 fell into doubt after the federal shutdown silenced operations in the St. Croix National Scenic Riverway, a national park that covers 255 miles along the St. Croix and Namekagon rivers in Wisconsin and Minnesota.

"We're disappointed. Things seemed to be going well," Chris Stein, the park's superintendent, said recently. "For us it's not about money, it's having a relationship where we capitalize on our strengths. The mission of Arcola and the park service were almost the same. I'd argue that every one of those thousands of visitors found a very special place that exceeded their expectations."

Ray Marshall, who chairs the all-volunteer Arcola Mills board of directors, agrees. But he also said the cash-strapped historic site incurs expenses when the federal agency operates from the mansion.

"We think having the park service there was great," said Marshall, whose board voted in September to deny a park service presence at Arcola Mills next year. "I don't feel it's a result of any disagreement between the NPS and Arcola. They don't have any money and we don't have any money."

Stein said the Arcola Mills decision was a shortsighted one, failing to take into account the positive image and public exposure brought to Arcola Mills. Over the past two years, Stein said, the park service gave $45,000 to Arcola Mills from an endowment fund administered by the St. Croix Valley Foundation. The agency isn't authorized to pay rent, he said, but the money covered utilities and other costs, including painting of the mansion.

In 2014, Stein said, money from the endowment will be spent at agency headquarters in St. Croix Falls, Wis., to help offset a $300,000 cut in his annual budget. More of the park's services, including the St. Croix Falls visitor center, will be handled by volunteers, he said.

"They gave us a proposal for next year that wasn't acceptable to us, that didn't involve any money, so I suppose that is the end of it," Marshall said. "It was a good thing that we had three years to experiment with this. We got a lot of people, a lot of exposure. It was good for Arcola, it was good for the park service."

But Marshall also said that having the agency for another year — or permanently — doesn't address "financial problems at Arcola." The historic site needs money for maintenance, improvements and snow removal.

In addition, he said, Washington County's May Township has told the Arcola board that changes to a special-use permit would be required for a permanent national visitor center. That would include Arcola paying thousands of dollars for a new parking lot and a paved road, he said.

Marshall said Arcola Mills has struggled to find a "sustainable" source of income, having tried unsuccessfully to market the mansion as a retreat center and to rent it for weddings and small classes. The foundation now is looking harder at developing the mill portion of the property, he said, because of its potential in telling the St. Croix's early lumberjack and logging history.

Jill Greenhalgh, a former paid executive director at Arcola Mills, said she was surprised at the "ousting" of the park service. "The intention was always to have it be open to the public as an interpretive and educational center in order to tell the story of the river — its past, present and future," she said. To that end, she said, she raised more than $1.2 million from foundations and donors to restore Arcola Mills.

"I would find it deeply disappointing if they were to try to use this historic St. Croix River site for private purposes. It would be a betrayal of the public's investment and trust," she said. Trading on the park service name and image, she said, would have opened the door to rich fundraising resources in the Twin Cities.

"They're the gold standard of organizations with national identity and integrity," she said.

Dianne Storti, who volunteered each of the three experimental seasons, said the familiar brown sign on nearby Hwy. 95 was a powerful draw: "I'm really saddened by the Arcola Mills' board decision. It's a real loss to the public. Arcola Mills is such a hidden treasure."