Protect our public property: disallow and invalidate Trademarks of National Parks and Historic places

Yosemite National Park has recently been subject to a forced name-change of many of its historic buildings and areas due to an out-going concessionaire secretly obtaining Trademarks on the names, including the name of the park itself: "Yosemite National Park". It is demanding $51million from the park for these Trademarks as a new concessionaire is taking over. As the park is a federal property kept for the public, these trademarks and their current use are unjust and should be invalidated. Further, the Trademark office should put in place regulations preventing names of federal public places, icons and property from being trademarked by non-government organizations without special consideration.