A record number of people visited the St. Croix National Scenic Riverway in 2014, but that statistic has more to do with improved counting than with a sudden upswing in park popularity.

The National Park Service (NPS) annual report recently released showed 671,582 people visited the park last year, topping the previous record of 625,549, logged in 1987. Boaters and canoeists accounted for most of the visitors last year, the majority of whom used the park from May through October.

"It's hard to say how many more visitors may be out there each year," said Julie Galonska, the riverway's chief of interpretation. "I really think it has more to do with us getting a better handle on the numbers of people out there and counting those people."

Documenting visits to the St. Croix riverway presents a more difficult challenge than at many other national parks because so many boat landings — 70 — fall within its vast boundaries.

The riverway, managed from NPS headquarters in St. Croix Falls, Wis., stretches over 255 miles on the St. Croix and Namekagon rivers in Minnesota and Wisconsin.

Unlike other national parks — such as Theodore Roosevelt in North Dakota and Yellowstone in Montana and Wyoming, which have just a few entrances where visitors pay to enter — the St. Croix riverway doesn't have traditional gateways to count people.

"If we collected a fee I would have a much better idea," Galonska said.

Instead, numbers come from a variety of sources — park visitor centers, permit holders, hunting licenses, traffic counters, daily counts of boats and canoes, backcountry overnight stays and outfitters.

At Wild River Outfitters in Grantsburg, Wis., owners Jerry Dorff and Marilyn Chesnik saw an uptick in business last summer after a couple of rainy seasons. They have been reporting customer numbers to the park service since 2002 — mostly level over the years — but Dorff said the latest statistics offer some encouragement.

"It might be indicative of economic recovery," he said. "People want to get outdoors."

More than two dozen outfitters that rent services for canoeing, kayaking and fishing document visitors for the NPS, as do tour boat operators.

The park service uses a mathematical formula to measure overall numbers, such as multiplying random counts of boats and canoes by 10.

The NPS doesn't measure visits to the "state zone" of the St. Croix River, which begins at the historic boomsite just north of Stillwater and experiences the heaviest recreational boating. The Minnesota Department of Natural Resources manages the St. Croix south to where it flows into the Mississippi River.

NPS statistics show that the other national park in the metro area, Mississippi National River and Recreation Area, attracted 85,637 visitors in 2014. Much like the St. Croix riverway, the 72-mile Mississippi park relies on visitor center numbers, boat tours and special events to count people.

The lowest recorded number of visits within St. Croix riverway boundaries — 188,400 — was in 2010, according to the NPS report. Statistics tracking riverway visitors have been kept since 1973. During that time, more than 16.4 million people have visited the riverway.

Galonska said attendance reporting in recent years may not have been as accurate as it could have been due to NPS budget and staff cuts, which depleted the ranks of full-time law enforcement rangers and left fewer available to count visitors.

Nevertheless, documenting and monitoring trends is more important to park managers than statistics on the overall number of visits, Galonska said.

"We tend to look at 'Where is visitation concentrated?' " she said. "Are there impacts on the river, on the water quality, on natural resources? Do we have erosion issues at certain landings? How are we managing the trends that are out there? Are we seeing trends emerging that people are using the river differently?"

Galonska said that regardless of how the 2014 visitor statistics were measured, they show substantial public interest in the riverway.

"I think those numbers show that it's a valuable recreational resource and a place people continue to come back to year after year," she said. "We definitely will keep an eye on this during the summer. It will be interesting to see how things rebound or don't rebound this year."

Kevin Giles • 651-925-5037