Alan Jackson, Easton Corbin and Gloriana will perform at Fort Sill, Okla., on Saturday (June 30) as an early Independence Day celebration for members of the military and their families. The show is open to the public. Fort Sill was founded more than 140 years ago on the plains of Oklahoma. It was added to the National Register of Historic Places in 1960 and is home to Army artillery and officer training programs. Jackson will also perform Thursday (June 28) at Red Rocks Amphitheatre in Morrison, Colo., and Friday at the United Spirit Arena in Lubbock, Texas.