Work begins Tuesday on a restoration of the St. Croix Boom Site, the place on the river where floating logs were gathered and sorted during Stillwater's lumber milling heyday.

The deteriorating national historic landmark, on Hwy. 95 about 2 miles north of Stillwater, will close to the public until construction is completed in midsummer, according to the Minnesota Department of Natural Resources. The work will be funded with a $500,000 federal grant.

The Boom Site opened in 1856, seven years after Washington County was formed and two years before Minnesota became a state. An estimated 15.5 billion feet of white pine logs cut farther north were stamped with owners' names and floated to the site, where men known as "boom rats" scurried over the slippery logs to organize them into "rafts" for sawmills downstream.

"It's the only place in the river where you can get to the river in a natural setting. It's a pretty unique place," said Marc Hugunin of Friends of the St. Croix Boom Site.

No trace remains of the operation, but the part of the river where logs were gathered is visible from three locations along the bluff.

The north end of what's now the St. Croix Boom Site became a roadside rest area on Hwy. 95 after the logging operation closed in 1914. The Boom Site, declared a national historic landmark in 1966, lies within the boundaries of the St. Croix National Scenic Riverway.

The south site, developed as a traditional "scenic view," will get a large National Park Service sign welcoming motorists to the riverway park area. Work there will include a repaved parking lot, new sidewalks accessible to people with disabilities and rain gardens for stormwater.

The middle site has a marker explaining the boom site's historic significance, another scenic view and concrete stairs leading to the riverfront. Boulders will be added around the parking area to keep motorists off the grass.

The former rest area — connected to the middle site by a pedestrian bridge across a ravine — will see the most reconstruction. The parking lot will be downsized, and green space will be added along with new curbs, gutters and sidewalks.

No changes will be made to the nearby public boat launch.

Public agencies and nonprofit groups involved in planning the Boom Site's look decided it should retain its natural appearance as much as possible, in keeping with the federally protected river nearby.

Hugunin said public comments showed a desire for more improvements, including a trail that would connect with the new Brown's Creek State Trail farther south at Stillwater.

More funding will be needed for additional work. However, Hugunin said, Boom Site visitors will notice a difference by midsummer even if other improvements don't come for five or 10 years.

"It will be a better experience for people after they get out of their cars," Hugunin said.