San Diego County as it was originally established when California entered the Union as a state in 1850 also included the larger parts, if not all, of the present counties of Inyo, San Bernadino, Riverside and Imperial. This monograph deals with but three or four of the many stage coach and mail lines which operated within the present confines of San Diego and Imperial counties during the period between 1857 and 1874. Their history along with that of the development of the roads which they used is an intriguing study and it is hoped that this mere beginning will be of some help to him who may pursue this subject further.
