Colonel Rudolph William Riefkohl (October 12, 1885 – November 13, 1950), was an officer in the United States Army, who played an instrumental role in helping the people of Poland overcome the 1919 typhus epidemic.

His younger brother was Frederick Lois Riefkohl, the first Puerto Rican to graduate from the United States Naval Academy and to be awarded the Navy Cross for his actions in World War I.

Upon his arrival in the town of Maunabo he met young Rudolph and asked the lad in German if he had a map of Puerto Rico (Emerson had lost his).

Riefkohl returned home, not knowing that Emerson was a spy, and quickly drew another map with a depiction of the major ports and harbors of Puerto Rico.

[8] According to the United States War Department, on April 1, 1918, Riefkohl served as Captain of Coastal Artillery at the Letterman Army Medical Center in Presidio of San Francisco, in California.

Upon realizing that Riefkohl was the lad that drew the map which he, Whitney, had handed to General Miles during the Spanish–American War, they became good friends.

Riefkohl was awarded the Polish Commemorative Medal for the War of 1919–21 and transferred to United States Army of Occupation in Germany.

As war broke out in Europe, in 1939, he was instrumental in the planning and construction of Punto Borinquen (Ramey) Air Base in Aguadilla.