He was fortunate to find an art instructor in the still rough and tumble Colorado, where his early drawings included big horn sheep, elk, bears, and the lynching of outlaw L. H. Musgrove, which occurred in Denver in November 1868.

In 1885 Proctor sold a homestead that he had acquired near Grand Lake, Colorado, and used the proceeds to move to New York City with the intention of studying art.

[7] He enrolled first in the National Academy of Design where he studied drawing and painting, and later, at the Art Students League of New York, where his interest in sculpture came to the fore.

His ability to capture animals in action, garnered in part from his days tracking them, coupled with his interest in all things Native American, opened a niche for Proctor, one that he parlayed into a long, successful career.

Proctor's output after he moved to New York City was prolific; among his creations in this period was the sculpture of the horse underneath William Tecumseh Sherman in Grand Army Plaza, bordering Central Park.

[12] While the building no longer exists, it did represent an intriguing collaboration between the preeminent architecture firm and one of the leading sculptors of wildlife of the day.

[14] In between commissions Proctor frequently returned to the West for rejuvenation and inspiration, seeking out members of various Native American tribes to pose for his works.