More than 200,000 people flooded the U.S. Forest Service with comments over the last month calling for the agency to reject a plan for roads and infrastructure that would enable construction of a mega-development on the Grand Canyon’s doorstep. The proposed roads, sewers and other utilities would pave the way for a multinational developer to transform the 580-resident community of Tusayan, Ariz., from a small, quiet tourist town into a sprawling complex of high-end homes, retail stores and restaurants only a mile from the Grand Canyon National Park boundary. The development threatens groundwater that feeds the Grand Canyon’s creeks, springs and seeps, endangering some of the park’s most important and biodiverse wildlife habitat.