Petrified wood is a fossil, and the specimens here are estimated to be 20-30 million years old. Petrification can take very little time under the right circumstances, but the longer the process continues, the harder the rocks become, and conifer trees are believed to petrify faster than deciduous trees. Much of the petrified wood in this park was collected within 8 miles of Lemmon, and an estimated 1100 tons of petrified wood and 100 tons of petrified grass were gathered to construct the park. The concentration of petrified wood surrounding Lemmon is described as denser than anywhere else in the world. Ole Quammen's vision for Petrified Wood Park became a reality in 1930, and construction began at the onset of the Great Depression, providing jobs and financial support to more than 30 men who otherwise would have been unemployed. These men earned $1.00 a day, said to be about $17.75 today. Most of the park was completed and dedicated in the summer of 1932, when 10,000 people from across the state attended the grand dedication ceremony, where four steers were butchered and barbecued and hundreds of gallons of coffee were prepared for the crowd. Quammen continued expanding the park until his sudden death in 1934. Its future was questioned many times, but in 1954 Quammen's daughter, Alice Olson, turned the property over to the City of Lemmon.