Cheyenne, WY – A conservative legal group is suing the federal government over protection of the Preble's Jumping Mouse. Colorado-based Mountain States Legal Foundation filed the lawsuit in U-S District Court in Cheyenne. It claims a decision to list the mouse as threatened on the Endangered Species List violates federal law. Mountain States President William Perry Pendley says the 1998 decision wasn't based on the best commercial and scientific data available. He's also protesting the designation of more than 30 thousand acres of land in Colorado and Wyoming as critical mouse habitat. Environmentalists say the lawsuit won't stand up in court. Some ranchers, meanwhile, support the effort and say they're watching the litigation carefully.