Camp Carleton was the largest of several military camps to be maintained at various times in the vicinity of San Bernardino

San Bernardino

San Bernardino, California is a large city in the Inland Empire Metropolitan Area of Southern California.San Bernardino may also refer to:-Landforms:*San Bernardino , a torrent that flows through the Italian province of Verbano-Cusio-Ossola...

. It was established in the fall of 1861 by Captain William A. McCleave and a detachment of the 1st California Cavalry to check any successionest activities in San Bernardino County. After the camp was flooded in the Great Flood of 1862

Great Flood of 1862

The Great Flood of 1862 or Noachian Deluge was the largest flood in the recorded history of Oregon, Nevada and California, occurring from December 1861 to January 1862. It was preceded by weeks of continuous rains that began in Oregon in November 1861 and continued into January 1862...

, the camp's garrison was moved to El Monte, where they established New Camp Carleton.