ROCKFORD, Ill. (WTVO) — Work is underway on a $50 million expansion at the Chicago Rockford International Airport after the FAA ruled in its favor against environmentalist groups.

The controversial “Bell Bowl Prairie” is a piece of land that activists and the Natural Land Institute say is home to the endangered Rusty Patch Bumble Bee.

On Wednesday, a federal court denied a motion by the Natural Land Institute to delay construction work until March 15th, in an effort to force the airport to wait until October to complete the project.

Supporters for the cause rallied at the Winnebago County Courthouse Wednesday night.

“We’ve given them opportunities for a redesign. We’ve come up with ways to fund the redesign. But it’s falling on deaf ears. It’s falling on bad ego, need to be right. It’s so disheartening,” said Natural Land Institute executive director Kerry Leigh.

Airport administrators have shouldered numerous delays in the expansion project, and say it will create hundreds of jobs for the region.

In 2019, the FAA cleared the Greater Rockford Airport Authority to start the operation, and construction began in 2020. The next year, the Illinois Department of Natural Resources (IDNR) identified the Rusty Patched Bumble Bee in an area near the project.

When Airport Authority was notified about the endangered insect, they stopped construction and the FAA consulted with the U.S. Fish and Wildlife Services (USFWS) about the Endangered Species Act regarding the bee and other species.

In October 2021, The Natural Land Institute (NLI) sued the FAA, USFWS, and Airport Authority, claiming they failed to comply with the National Environmental Policy Act (NEPA) and with the Endangered Species Protection Act in a federal court case.

Work was paused in 2022.

“Chicago Rockford International Airport will retain more than six acres of the Bell Bowl Prairie. This includes more than three acres of high-quality prairie. Any excavation and shrub and brush clearing work in the project area will occur between October 15 through March 15 to avoid impacts to the Rusty Patched Bumble Bee and avoid the prime nesting seasons for the black-billed cuckoo and the upland sandpiper,” the Federal Aviation Administration wrote in its decision on Monday.