The first tower was a unique ground-mount two-level peak roof structure built in 1913. This was replaced in the 1930s with a 75' X-Brace steel tower with 7'x7' Aeromoter cab. The tower height was lowered to 20' in the late 1940s. A C2 Fireman/Lookout 19'x30' ground cabin was also contructed - a Region 5 BC-201 design. In 1951, that lookout was replaced with a 35' H-Brace steel tower with a modern C-10 13'x13' all steel live in cab. In 1964, the AT&T telephone company constructed a telephone relay building on the exact site of the lookout.

They agreed to add a tower and cab to the roof of the building. The cab was unique in design. The Forest Service discontinued use of the lookout in the late 1970s/early 1980s. AT&T removed the cab by 1988. The tower and catwalk still stand on top of the relay building. Santiago Peak is known as "The Talking Mountain", the busiest communications site in the United States. The peak is the highest point in Orange County and the Santa Ana Mountains at 5687'.