Two Southern California Trade Trails
- Author(s): Johnston, Francis J
- et al.
It is generally considered by historians that Spanish overland communication from Upper California to Mexico by way of Sonora ceased with the abandonment of the Anza Trail after the Colorado River Campaign of 1781-1783. Communication was maintained by sea, either direct from ports in Upper California or by courier to Lower California and thence to the mainland by sea (Brumgardt 1976:83).