It's Washington County's forgotten park, an alluring but overgrown natural area with crumbling roads and an entrance largely hidden to anyone who doesn't have a map.

But no more.

Starting in March, Cottage Grove Ravine Regional Park will undergo the first steps in an ambitious $3.5 million overhaul to make it more inviting, useful and visible.

Initial improvements include a new entrance road and trails, but eventually the park will have a substantially new look and purpose.

Residents are disappointed the park will be closed for a year while the work is done, but they're also excited about the changes, said Karla Bigham, who represents the Cottage Grove area on the Washington County Board.

"It's a quiet park but it's a tired park," she said. "These changes and upgrades are needed, long time coming."

Construction will come in phases beginning March 1, the day the park closes. County commissioners approved contracts Tuesday to remove nearly 800 trees, which will make room for trails and a new interior road and open more land to sunlight.

And the South Washington County Watershed District is leading a project to stabilize the ravine running the length of the park. That work, beginning this summer, will help protect the ravine against erosion from flash floods and water overflow and reduce phosphorus runoff into the lake, said County Engineer Wayne Sandberg.

"We're preparing the canvas for what we want to paint," he said.

In the second phase of the park project, not yet scheduled, county officials envision a larger and updated playground, new restrooms and an improved pavilion. Sandberg said the plan also might include a Nordic center for skiers, and sites for group camping.

The county's southernmost park, Cottage Grove Ravine is known for its wildlife and forests, fishing on Ravine Lake, skiing and hiking trails, and a picnic and playground area.

But the park also is known for buckthorn and other invasive plants, poor drainage, inadequate parking and restrooms, and that off-the-beaten-path entrance.

At 550 acres, it's among the smallest of the seven Washington County parks, nestled in a fold in the terrain from which nearby urban developments can't be seen. County records show the first large parcels of land for the park were acquired between 1969 and 1971.

The park often floods in the spring, Bigham said, but new road construction should eliminate those problems.

The county will move the park entrance from the south end to Keats Avenue (County Road 19) on the west to improve visibility. That work will be done in conjunction with construction of a new roundabout farther south at the intersection with Innovation Road, Sandberg said.

Addressing concerns raised by the U.S. Army Corps of Engineers, trees in the park must be cut down before the end of March while the endangered northern long-eared bats are inactive, Sandberg said. S & A Land Clearing, Inc., of Hugo, will do the removal for $119,600.

Road and trail improvements, costing about $73,000, will be entirely funded by county bonds. About $39,000 in ravine improvements will be funded by the watershed district.

"This park is kind of a forgotten park. It's hard to get to, to find the entrance, and people don't know it exists," Sandberg said.

Kevin Giles • 651-925-5037