Mount Rex is an isolated mountain (1,105 m) which rises above the interior ice surface of Palmer Land

Palmer Land

Palmer Land is that portion of the Antarctic Peninsula which lies south of a line joining Cape Jeremy and Cape Agassiz. This application of Palmer Land is consistent with the 1964 agreement between US-ACAN and UK-APC, in which the name Antarctic Peninsula was approved for the major peninsula of...

 about 55 miles south-southeast of FitzGerald Bluffs

FitzGerald Bluffs

FitzGerald Bluffs are prominent north-facing bluffs, 9 nautical miles long, located 30 nautical miles south of Snow Nunataks. Discovered by Ronne Antarctic Research Expedition under Finn Ronne, who named the bluffs after Gerald FitzGerald, Chief Topographic Engineer, United States Geological...

. It was discovered and photographed from the air on 23 November 1935 by Lincoln Ellsworth

Lincoln Ellsworth

Lincoln Ellsworth was an arctic explorer from the United States.-Birth:He was born on May 12, 1880 to James Ellsworth and Eva Frances Butler in Chicago, Illinois...

 (Geographical Review

Geographical Review

The Geographical Review is an academic journal of the American Geographical Society. Currently published quarterly in January, April, July, and October. The periodicals are devoted exclusively to geography and contain original articles on all aspects of the discipline. The "Geographical Record"...

, July 1936, p. 459, Fig. 16). The feature was resighted by the Ronne Antarctic Research Expedition

Ronne Antarctic Research Expedition

The Ronne Antarctic Research Expedition was an expedition from 1947-1948 which researched the area surrounding the head of the Weddell Sea in Antarctica.-Background:...

 (RARE) (1947–48) under Finn Ronne

Finn Ronne

Finn Ronne was a U.S. Antarctic explorer.-Background:Finn Ronne was born in Horten, in Vestfold county, Norway. His father, Martin Rønne , was a polar explorer and served in Roald Amundsen's successful expedition to the South Pole...

, who named it for Lt. Cdr. Daniel F. Rex, USN, of the Office of Naval Research

Office of Naval Research

The Office of Naval Research , headquartered in Arlington, Virginia , is the office within the United States Department of the Navy that coordinates, executes, and promotes the science and technology programs of the U.S...

, who made important contributions to the planning of the scientific research program and the equipping of the expedition.