Number one on this list is the Reed family. They are the largest land owners with 1.4 million acres of land. Now, they didn’t purchase all this land at once. It took years to accumulate this amount of acres, in fact it took generations to get this amount of land.  
They have been purchasing land since the late 1800’s. The land was mainly purchased over the years to grow their lumber empire in the Northwest. In 2014 came their largest purchase of 600,000 acres of prime timberland in Orgeon. This was one of the largest land purchases in the U.S since John Malone, who purchased 1 million acres in Maine in 2011.