Edited sentence: Disruption of the preserves jeopardizes habitat for already vulnerable threatened and endangered plants, Byssus Skipper butterflies and Blanding's turtles.In addition, many rare plants and animals thrive in the preserves.Many have assessed that this proposed highway serves no justifiable transportation need and that only local developers would benefit.On June 12, 2012, The Iowa Transportation Commission will be voting on its five-year plan for highway construction.One of the projects proposed for inclusion in the plan is the extension of Highway 100 in Linn County.The Department of Transportation claims to have mitigated this environmental destruction, but such a significant impact to such a unique ecosystem cannot be adequately mitigated.The Sierra Club opposes this project because the highway would slice through a county nature preserve and adjacent to a state nature preserve.The extension would destroy one of the last remaining remnants of native sand prairie in Iowa