Milton Norman Nathanson (1910-2000) was a prominent water rights attorney, specializing in Colorado River water issues, specifically "The Law of the River." Born on December 19, 1910 in Philadelphia, Nathanson attended college in his home state at the University of Pennsylvania, graduating with a Bachelor of Arts from its Wharton School of Finance and Commerce in 1932 before receiving his Juris Doctorate from Penn Law in 1935. In 1941, Nathanson joined the Office of the Solicitor at the United States Department of Interior in Washington, D.C. after briefly practicing law in the private sector; he served in the counterintelligence division of the United States Army during the Second World War from 1943-1945 before returning to Washington, D.C. following the war.

Nathanson transferred to the Department of Interior's Los Angeles office in 1947, where he served as Assistant Regional Solicitor until the early 1970s, and then Field Solicitor until his retirement in 1975. During his time at the Department of Interior's Los Angeles office, Nathanson was involved in many important projects and cases regarding Colorado River water issues, including the protracted Arizona versus California litigation, the authorization and construction of the Central Arizona Project, and the passage of the Colorado River Basin Salinity Control Act.

Nathanson continued to act as a special consultant to the Department of Interior after his retirement, and later served as legal consultant to the Coachella Valley Water District for nearly two decades during its protracted litigation with the Imperial Irrigation District and the Metropolitan Water District of Southern California regarding their respective Colorado River water rights and allotments. In addition to his consulting work, Nathanson was appointed by Governor Jerry Brown as a Public Member of the Colorado River Board of California, a position he held from 1975 until 1981; he also served as a technical expert for the United Nations, and as Water Rights Expert for the State Department of Guyana, helping to draft the country's water code.

Demonstrating his stature as one of the leading experts of "The Law of the River" of his time, Nathanson was commissioned by the Department of the Interior to author the book Updating the Hoover Dam Documents, which he completed in 1978 for publication in 1980. Nathanson died on October 29, 2000.