 While the tree had long been known about for its size , the unique status of the Mingo Oak was not recognized until 1931 , when John Keadle and Leonard Bradshaw of Williamson took measurements of the tree , and found it to be the largest living white oak in the world . Various estimates place the Mingo Oak 's seeding between 1354 and 1361 AD . Using borings from the tree , the Smithsonian Institution determined that the Mingo Oak was the oldest tree of its species . The Island Creek Coal Company , the North East Lumber Company , and the Cole and Crane Real Estate Trust leased 1 @.@ 5 acres ( 0 @.@ 61 ha ) encompassing the tree to the West Virginia Game , Fish , and Forestry Commission for it to be managed as a state park for the life of the tree . The commission cleared the surrounding land and made improvements such as seating and picnic accommodations for visitors . 
