Clearing the way for nature at Cottage Grove's Ravine Park

Tom Bell remembers a time when he could spend hours hiking Cottage Grove Ravine Regional Park and stroll through the open patches known as "goat" or "dry'' prairies.

That was decades ago, before buckthorn, honeysuckle and other invasive species began overrunning the park, crowding out native oak forests and savannas and blotting out those small hilltop prairies.

But now, thanks to a multiyear effort by Washington County to remove invasive species and restore oak woodlands and prairies, parts of the park are beginning to look like they did when Bell, 83, began visiting years ago.

Contractors and volunteers wielding chain saws and brush saws cleared 35 acres of buckthorn over the fall and winter, working from a natural resource management plan the nonprofit Friends of the Mississippi River developed for the southern half of the 515-acre park in 2012.

The cleanup resulted in more open views of the park and Ravine Lake and more room to wander through the woods.

"It's really nice to be able to see through the woods," said Bell, a retired Park High School biology teacher who lives on Grey Cloud Island and who began walking the park more than 50 years ago.

Crews will return to the cleared area and use manual, chemical and mechanical efforts to fight any re-emergence of buckthorn, Dan MacSwain, natural resources coordinator for Washington County parks, said.

The next step in the restoration will be to clear 53 acres of parkland adjacent to the 35 acres cleared this year, Washington County parks manager Peter Mott said. The county has received grants to help pay for the work from the state's Outdoor Heritage Fund and the 3M Foundation.

"We expect at least a decade's worth of work cleaning the park out," Mott said. "We're learning to manage these invasive species so that we can continue this work internally and with voluntary crews."

The overgrowth was the result of 30 to 40 years of management during which two things were absent: fire, in the form of prescribed burns, and invasive species control, Mott said.

MacSwain hopes to conduct some controlled burns through the forest as another measure to keep buckthorn from returning.

"By not allowing fire to enter into that landscape, a process of ecological change began to occur," Mott said. "After a few decades, [invasive species] really started to dominate the landscape. And these invasive species are quite good at promulgating themselves, so the condition of the park is that it's pretty severely infested."

The development plans likely will include improvements to the park's access road and roadway, which Mott said are in horrible condition. Moving the park's entry from the frontage road on Hwy. 61 to Keats Avenue is another possibility, as are establishing a building or picnic shelter and "flush restroom facilities" to replace existing composting toilets.

The plan also will address possible adjustments to trails because the South Washington Watershed District plans to begin conveying stormwater through the park, Mott said.

Todd Nelson is a freelance writer in Woodbury. His e-mail address is todd_nelson@mac.com.