I recently noticed a handful of very similar but slightly different postcards in Tom Pulley's amazing Orange County postcard collection. Each image was an elaborate map of the Newport Harbor area. (The one shown above is from about 1931, and the one immediately below is probably from 1939. Click any image to enlarge it.) The maps are detailed enough that even the landmark Arches gas station is shown. Another detail I noticed was the name "Putnam," signed in the corner of one card.
Claude George Putnam was an illustrator who lived in Glendale and worked in Los Angeles. Born in Michigan in 1884, he attended the Académie de la Grande Chaumière in Paris. He did advertisements, book plates, model-making, engraving, printing, and cartography. He was locally well-known and was the founder and first president of the Advertising Art Association of Southern California.
He was also a longtime member and officer of the Newport Harbor Yacht Club, which is how he came to create a promotional map for the Newport Harbor Chamber of Commerce. The postcards are just photographs of one portion of the 18" x 16" map/poster, which also included detailed text and a smaller map on the back. These posters were updated every so often. An image of the 1944 version of the poster is shown below. Notice how many more streets are shown.
Putnam did a similarly detailed map for the developers of Beverly Hills in 1912 and later created various maps of California history and the Old West.
The 1944 Newport Harbor map, appropriated by local Howard Doss for his own postcards (shown below,) also includes a plug for the Orange County Harbor District. Newport Bay was developed into a more functional harbor in the 1930s, and was officially dedicated in 1936.
The Sport Fishing Association of Newport Harbor also produced a line-art version of the 1944 map, which mainly differed in the number of giant fish and fishing boats shown in the water.
The color map below is from about 1950, and shows the spot where Hoag Memorial Hospital will soon be built. Notice that not only our current airport, but also the short-lived Costa Mesa airport is depicted. Also notice the 23-foot "sea serpent," seen in 1904 (which turned out to be an oarfish, by the way).
But Putnam's most famous map was probably the colorful map he did in 1946 (shown below) as part of the "Roads to Romance" campaign to promote travel in Southern California.
Putnam died at Hoag Hospital in 1955, but we're still enjoying his work today.