Lakes was a part-time professor at what later became the
Colorado School of Mines. Having sent a
fossilized vertebra specimen from the
Morrison Formation in the
Kansas Territory to
Othniel Charles Marsh in 1877, he was then employed by Marsh to seek other discoveries, in the so-called
Bone Wars. He went on to unearth fossilized remains of
Stegosaurus,
Apatosaurus,
Camptosaurus, and
Allosaurus. One of Lakes's students, Peter Dotson, has been credited with finding one of the first fossils of Tyrannosaurus Rex, a tooth, in 1874 while hunting fossils with him on South Table Mountain in Golden Colorado. Lakes sent the tooth to Marsh identifying it as a "saurian tooth". It remained unidentified until around 2000 when it was rediscovered by Kenneth Carpenter of the Denver Museum of Nature and Science while he was looking at Lakes's fossils at the Yale Peabody Museum. While he was working for Marsh at
Como Bluff, Lakes was visited by Marsh's Bone Wars opponent,
Edward Drinker Cope. His collaboration with both men was inadvertently the source of increased animosity between them. Lakes made the original discovery of the fossils in the formation of the
Dinosaur Ridge near
Morrison, Colorado. Lakes also drilled several test
oil wells in the
Golden and Morrison area, however they were not successful producing wells. During this time, he also worked as a teacher at what is now the
Colorado School of Mines and as a clergyman. When he retired from fossil hunting, he went on to work for the
U.S. Geological Survey. He edited a succession of geological and mining journals. His byline appears on over 800 newspaper and journal articles. Lakes and his two well-educated sons eventually went into business as mining engineers, relocating from
Colorado to
Ymir, British Columbia in 1912. Arthur Lakes died there in 1917, still "tanned from the outdoors life he led." ==Awards and honors==