In the 1920s, grazing and development threatened the future of the saguaro as forests of mature cactuses were chopped down for new roads and livestock trampled seedlings. Fearing destruction of the Southwest's saguaro forests, local residents supported an effort led by Homer Shantz that began in 1928 to protect giant saguaros. President Hoover authorized Saguaro National Monument in 1933, President Kennedy added the Tucson Mountains in 1961, Congress designated 71,400 acres as wilderness in 1976, and Congress designated Saguaro National Park in 1994, protecting giant saguaros for generations to come.