The Civilian Conservation Corps was a New Deal program developed under President Franklin D. Roosevelt to provide jobs to the unemployed during the Great Depression of the 1930s. Initially designed to employ young men and later expanded to include World War I veterans, the program was used to improve the 15,000 acres recently acquired by the State of Texas for Palo Duro Canyon State Park. The first three companies of enrollees, made up of World War I veterans, arrived in Amarillo by train on July 11 and 12, 1933, and after establishing camp, their first task was constructing the road from the canyon rim to its floor. A fourth veterans company arrived in December 1933. The early veterans groups at the canyon were initially integrated, but the African American troops were reassigned to Sweetwater, Texas, in 1934. Two companies of segregated African American enrollees arrived from east Texas in August 1935. The final group of workers in the canyon was composed of youth members, and when that group left in December 1937, the project at Palo Duro Canyon was one of the few to include workers from each of the three special groups: veterans, African Americans, and juveniles. From 1933 until 1937, the corps completed public buildings such as El Coronado Lodge, cabins built of native sandstone, roads, bridges, culverts, and hiking and bridle trails, many of which are still in use today.