It is a part of the Northeast Greenland National Park.

[1][2] The territory was named by Robert Peary after US President Theodore Roosevelt (1858 – 1919).

The peninsula is mountainous, deeply cut by glaciated areas.

[4] The highest point is a 1,555 metres (5,102 ft) summit found in the southern zone of the central part of the peninsula.

[5] American geologist William E. Davies called the long mountain system to the north of J.P. Koch Fjord and Frederick E. Hyde Fjord the "Nansen-Jensen Alps", with the westernmost foothills in neighboring Nansen Land, stretching past the De Long Fjord area across Roosevelt Land and the Roosevelt Range, and reaching all the way to Johannes V. Jensen Land in the east.