More info: The peak, straddling the Riverside-Orange county line, is Orange County's tallest point. Santiago Peak and Modjeska Peak combine to form Saddleback Mountain. Santiago Peak is the southern mountain of the Saddleback formation and is the highest point in Orange County at 1,734mtrs. Saddleback Mountain is actually two peaks, Santiago Peak and the lower Modjeska Peak. Saddleback Mountain can be seen from most of Orange County and dominates the skyline. It is named after Santiago Creek, which starts on the upper slopes of the mountains and then flows into the Santa Ana River, eventually joining the ocean at Huntingdon Beach.
From the summit of Santiago Peak, you can see the larger Southern California peaks like Mount San Gorgonio, Mount San Jacinto, and Mount San Antonio.
The top of the Peak is covered with many microwave and telecommunication antennas, providing radio coverage over much of Los Angeles, Orange, San Bernardino, Riverside, and San Diego counties. It houses both broadcast and two-way communications facilities on virtually every frequency band, including FM broadcast, VHF low- and high-band, UHF, 800/900 MHz, and microwave.