Four months after a court victory over environmentalists, state highway officials are pushing ahead with their plans to start work this summer on the first segment of the long-planned Interstate 69 extension between Evansville and Indianapolis.

State contractors began clearing trees and homes last month from a nearly 2-mile-long stretch in Gibson County to prepare for construction of the first piece of the 142-mile highway.

Andy Dietrick, a spokesman for the Indiana Department of Transportation, said Tuesday that two homes and two outbuildings had been razed and about 100 trees felled in that tract.

He said INDOT faced an April 15 deadline to clear the plot’s trees because removing them any later would have risked harming the federally endangered Indiana bat, a thumb-sized animal that emerges from caves in the spring to roost and reproduce in trees over the summer.

“If the bats had come out of their caves and roosted in those trees with their young then we wouldn’t have been able to remove those trees. But we met that deadline,” Dietrick said.

With site clearance proceeding, he said the state plans to open bidding Wednesday on a contract to build a 1.77-mile section of the highway from Interstate 64 to State Road 68.

That small stretch is part of the highway’s 13-mile Section 1 that will run to Oakland City and be the first segment built.

Dietrick said construction is set to start in midsummer on those initial 1.77 miles. He said Section 1 is the only part of the six-section highway that’s so far received final approval from the Federal Highway Administration.

Environmentalists oppose the highway, which will cost between $1.73 billion and $1.83 billion, because it will cut across wetlands, woodlands, sensitive cave ecosystems and farmland.

On Dec. 10, a federal judge ruled against environmental groups who had sued to try to block the highway. Dietrick said that ruling cleared the way for INDOT to start work on the first part of the highway across rural southwestern Indiana, which is now served mainly by two-lane roads.

As work proceeds on the highway’s short first portion, law enforcement are keeping close watch on the bulldozers, trucks and other equipment being used at the Gibson County site.

Dietrick said INDOT is concerned about veiled threats to the project, including an Internet posting purportedly from the radical environmental group Earth First! that states: “We will never let them build this road.”

Gibson County Sheriff Allen Harmon said his deputies began conducting extra patrols after INDOT and contractor Bernardin Lochmueller & Associates passed on word of the possible threats.

So far, he said, there’s been no trouble and no arrests.

“I’m hoping that we can keep it to where everyone can voice their opinion in a peaceful manner,” Harmon said.