MADISON, Wis. -- Madison police said that illicit and illegal activity at Olin Park continues to be a big problem.

A new police study to be reviewed by the City Parks Commission said that nine out of every 10 people in the trail section of Olin Park are visiting the park for illicit or illegal activity.

A recent pilot program allowing leashed dogs at the conservation park hasn't really helped reduce the problem, police said.

So parks officials said they plan to fight the problem by cutting back invasive plant vegetation, which is good for the oak savanna.

"What that also does is take away some of those hiding places that have, by nature, developed themselves, and it kind of removes that," said Kevin Briske, city parks superintendent.

The parks superintendent said annual burns of the savanna are also key, as is outreach to community groups that might increase their usage of the woods.