NEW ORLEANS (AP) - An environmental group says it plans to sue the federal government to protect two species of turtle found only in Louisiana and Mississippi.

  

The Center for Biological Diversity on Tuesday released a copy of its letter to Interior Department Secretary Ryan Zinke. It says the center will sue the U.S. Fish and Wildlife Service in 60 days for failing to act on a petition to designate the Pascagoula map turtle and the Pearl River map turtle as threatened or endangered.

  

The center says environmental groups sought protection for the turtles in 2010.

  

The center says a proposed Pearl River dam project in Mississippi's Hinds and Rankin counties is among the threats facing the turtles.

  

The wildlife service referred requests for comment to the Justice Department, which didn't immediately respond.