After occupying a space in Anthony Chabot Regional Park for nearly 53 years, the Chabot Gun Club will lose its home on the marksmanship range within three weeks.

To prepare for the closure, the Castro Valley club’s directors are leaving the public range open only until Monday before cleaning up and hauling their property away over the next two weeks. The East Bay Regional Park District, which owns the 65-acre marksmanship range, has given the gun club until Sept. 20 to leave.

The closure ends a nearly two-year battle between the club and the park district to operate the popular and well-known marksmanship range, Chabot Gun Club President Dennis Staats said.

“You know what, it’s very discouraging and it’s very sad, but (the park district) is a government agency that, in my opinion, has next to no oversight,” Staats said in an interview Tuesday.

“Are they trying to serve their constituents and their communities? Of course. I’m not saying they’re the mafia or something, but the problem is that they appear to be easily deluded with regard to what their mission is to the public and what their funding is,” he said.

Under its current lease, the gun club operates, manages and provides security for the gun range.

The marksmanship range will be secured immediately after the club leaves, East Bay Regional Park District spokeswoman Carolyn Jones said. All buildings on the marksmanship range, including the main office, classrooms and ranges, will be demolished, she said.

An estimated $2.5 million to $20 million environmental cleanup will take place over several years before the property is converted to open space. Those costs vary “depending on cleanup methodology used to remove contaminants from the gun range site,” according to park district documents.

Though the Chabot Gun Club does not track the number of people who use the gun range, park district and club records show there were 35,000 individual visits last year.

In 2013, four East Bay police departments used the gun range for training and firearms qualification purposes, including Moraga, Berkeley, Piedmont and Emeryville. Government contractors, along with the Federal Correction Institute, U.S. Department of Justice, U.S. Coast Guard and Military Sealift Command, also used the gun range in 2013.

The Chabot Gun Club has about 1,000 members. Staats said the club will continue to operate even after it leaves the gun range, but pointed out that the closure will severely limit the number of places where members and other gun users can go. The Chabot gun range makes up a significant chunk of individual spaces where gun users can practice in the Bay Area, Staats said.

“That’s a rather onerous problem, because there have been a number of range closures in the Bay Area certainly over the last several years,” Staats said.

“What’s happening up there isn’t just about the members being displaced from a place to shoot, it’s about the public and community being now deprived of a recreational shooting space,” he said.

Discussions to close the gun range arose last year after an East Bay Regional Park District-commissioned environmental study raised concerns that the gun club could not afford to contain lead pollution in the area, upgrade old buildings and further reduce noise impacts.

The 39-page report estimated it would cost about $2.4 million to $3.4 million to make those improvements on top of $190,000 in annual operating and maintenance costs.

Staats disputes those estimates and says it may actually cost even more to clean up the gun range site once it is closed and subject to greater federal environmental regulations.

In March, park district directors terminated the club’s concession permit, giving it a one-year lease extension to wrap up operations.

But gun club directors decided to move out earlier after they felt park district leaders attached costly and burdensome conditions to the lease extension, Staats said.

“The Chabot Gun Club board has done everything in its power to protect its members, patrons, employees, and vendors during this entire process,” he wrote in an Aug. 25 open letter to club members and gun range users.

Contact Darin Moriki at 510-293-2480 or follow him at Twitter.com/darinmoriki.