A Sweet Deal

From Wikipedia: The San Diego and Arizona Railway (reporting mark SDA) was a short line U.S. railroad founded by entrepreneur John D. Spreckels - of the Spreckels Sugar empire - (The entrepreneur's many business ventures included the Hotel del Coronado and the San Diego and Arizona

Railway, both of which are credited with helping San Diego develop into a major commercial center) and dubbed "The Impossible Railroad" by engineers of its day due to the immense logistical challenges involved. Established in part to provide San Diego with a direct transcontinental rail link to the east by connecting with the Southern Pacific Railroad (which secretly provided the funding for the endeavor) lines in El Centro, California,

the 148-mile (238 km) route of the SD&A originated in San Diego, California and terminated in El Centro, California.

The company charter was executed on December 14, 1906, and the groundbreaking ceremony was held the following September. Numerous delays (including government intervention during World War I) delayed the completion of the line to November 15, 1919. Damage to the lines from both

natural disasters and sabotage exerted great financial pressure on the company, and in 1932 Spreckels' heirs sold their interests in the railroad to the Southern Pacific, which was named the San Diego & Arizona Eastern Railway (SD&AE).

These three postcards show two locations on the Railroad about half way between El Centro and San Diego, California. The first two post cards are published by the M. Kashower company out of Los Angeles, California from 1914 to 1934. The company focused mostly on the southern California area; this post card is an example of that. If you look in the bottom right hand corner of the post card, you can see a number. It doesn't show up well on the scans above so here is a close-up:

If you look very carefully, you can make out a 23404 among the rocks. The bottom image, above, is a copy of this post card, but by a different publisher: H. L. Christiance out of San Diego, California. The number is missing in the bottom right. I did some research trying to find out how long this company was around. All I could find were images of a book they published in 1915.
The M. Kashower company has a great logo:

They want you to know that they are from California, the Bear State. This is a depiction of a grizzly bear between the company's two letters of its name.