 The railroad won the court battle and then handed the land over to the federal government.The site was first officially established as "Lewis and Clark Cavern National Monument" on May 11, 1908, but was not fully surveyed and declared until May 16, 1911, by President Taft as .The limestone cave is named after the explorers Meriwether Lewis and William Clark since the cavern overlooks over of the trail from the Lewis and Clark Expedition along the Jefferson River, although Lewis and Clark never saw the cavern.