On back: "From seemingly inexhaustible reservoirs, hundreds of wells have given forth their wealth estimated to be in excess of $850,000,000 since the day oil was discovered here in 1921. Approximately 180 oil companies operate on Signal Hill and nearby fields. Like sentinels guarding the great treasure chest of black and gold, more than 2100 derricks stud the mound like a giant pin-cushion."
Publisher's serial number: 13733
Natural color post card made in U.S. A. by E. K. Kropp Co., Milwaukee, Wis."E. K. C. Co." printed in four corners of the stamp box.