Modernizing Access to Our Public Land Act This bill directs the Department of the Interior, the Forest Service, and the U.S. Army Corps of Engineers to jointly develop and adopt interagency standards to ensure compatibility and interoperability among federal databases for the collection and dissemination of outdoor recreation data related to federal lands. Interior, the Forest Service, and the Corps of Engineers must digitize and publish geographic information system mapping data that includes federal interests, including easements and rights-of-way, in private land; status information as to whether roads and trails are open or closed; the dates on which roads and trails are seasonally opened and closed; the types of vehicles that are allowed on each segment of roads and trails; the boundaries of areas where hunting or recreational shooting is regulated or closed; and the boundaries of any portion of a body of water that is closed to entry, is closed to watercraft, or has horsepower limitations for watercraft.