The city of Minnetonka will plant some new patches of wildflowers and native grasses to settle a dispute over a new mountain bike trail that will wind through one of the last known refuges of the rusty patched bumblebee.

The fat and fuzzy species of bee, on the brink of extinction, has something of a haven at Minnetonka's Lone Lake Park, causing concern from environmental groups and neighbors over the impact of the planned 4.7-mile bike trail.

To limit any harm to the endangered bee, the city agreed to convert an acre of the park into pollinator habitat. It will replace mowed lawn with flowering plants and grasses that are critical for the bumblebee's survival. The city will also limit pesticide use, help homeowners join a state program to plant their own pollinator gardens — as well as help homeowners near the park pay for planting those gardens. The city also agreed to hire a bee expert to monitor trail construction and survey how the insects are doing inside the park for at least three years after the bike path is finished.

Leslie Yetka, Minnetonka natural resource manager, said she's confident the city will minimize the effects on the bees as much as possible.

"We recognize that we need to make sure we're increasing the amount of habitat available for the bees, specifically getting flowers and more food on the landscape," Yetka said.

The Center for Biological Diversity, an environmental group that focuses on endangered species, filed its intent to sue the city in August, saying the trail would remove about 6 acres of critical habitat for the bumblebee.

A common bumblebee hovered over a wildflower in Lone Lake Park in Minnetonka in 2018.

At the time, the group said it wasn't trying to kill the bike trail but wanted to work with the city to mitigate the impacts. City officials were willing to do exactly that, said Tara Cornelisse, senior scientist for the center's endangered species program.

The acre of new habitat, especially, will help the bee population hold on in the park, Cornelisse said. The three-year survey will provide better data on how the bees are doing, where in the park they are going and whether or not the trail hurts them, she said.

"This kind of conservation that the city is going to do is so important because Lone Lake Park is such a critical habitat for the bee," she said.

Surveys suggest the Lone Lake Park population might represent as much as 13% of the rusty patched bumblebees left in the state, and up to 6% of the remaining population in North America.

The U.S. Fish and Wildlife Service estimates the bee's population has plunged by about 90% in the last 20 years. The decline is largely because of pesticides, disease and habitat loss. The agency estimates the bees, identifiable by their plump size and a rust-colored patch on their back, are left in only 0.1% of their historical range.

Over the past few years, most rusty patched bumblebee sightings have been recorded in suburban areas around Chicago, Milwaukee and the Twin Cities. Biologists aren't sure if that's because the cities have more people around to spot the insects, or if it is a sign that the bees have been using urban gardens as havens after being pushed from farms and rural areas by a decadeslong switch to intensive row cropping in the region.

The city of Minnetonka estimates the pollinator habitat and survey work will cost $20,000 to $50,000.

The mountain bike trail, which is expected to be completed by the end of October, has met stiff opposition since it was proposed several years ago.

Earlier, state courts ruled against a group of Minnetonka homeowners and park users who fought the trail and demanded the city first conduct an environmental assessment.

Mayor Brad Wiersum said the city is pleased to work with the center to ensure that the bumblebee, which was named the state bee in 2019, is protected.

"Preserving and protecting Minnetonka's distinctive natural environment ranks among the city's top priorities," Wiersum said.

Greg Stanley • 612-673-4882