Mikkelsen was born on 23 December 1880, in
Vester Brønderslev,
Jutland, the son of Maren Nielsen and educator
Aksel Mikkelsen. His siblings included Thorvald Mikkelsen (1885-1962) and author and translator
Auslaug Møller. In 1900, he served in the
Georg Carl Amdrup expedition to
Christian IX Land in East Greenland. He then served in the
Baldwin-Ziegler North Pole Expedition to
Franz Joseph Land, which took place from 1900 to 1902. With
Ernest de Koven Leffingwell, he organized the Anglo-American polar expedition which wintered off
Flaxman Island, Alaska, in 1906–07. They lost their ship, but in a
sledge journey over the ice, they located the
continental shelf of the
Arctic Ocean, offshore, where in a span of , the sea's depth increased from to more than . Mikkelsen organized an expedition to map the northeast coast of Greenland and to recover the bodies of the ill-fated
Denmark expedition leader,
Ludvig Mylius-Erichsen, and cartographer,
Niels Peter Høeg Hagen, in addition to their records. For this task, Mikkelsen wintered from 1909 to 1910 at
Shannon Island. His wooden ship, the
Alabama, became trapped in the ice of Shannon Island and, while he was exploring, the rest of the party returned home on a
whaler. Remaining with his engineer, Iver Iversen, Mikkelsen succeeded through a series of hazardous sledge journeys. They recovered the lost records in a
cairn at the head of
Danmark Fjord, discovering that "the
Peary Channel does not exist." The two explorers returned to Shannon Island to find the crew gone, but they used salvaged timbers and planking to erect a small cottage. Mikkelsen and Iversen then spent two winters at the cottage before they were rescued, in the direst of extremities, by a Norwegian whaler in the summer of 1912. In 1924, he led an expedition to settle what later came to be
Scoresbysund. In 1970, on his 90th birthday, a national tribute was paid to him in Denmark; he died in Copenhagen a few months later on 1 May 1971. In 2009, the
Royal Danish Navy named the second
Knud Rasmussen class patrol vessel the . The
Ejnar Mikkelsen Range is named after him. == Works ==