Penrose formed the Utah Copper Company in 1903. He worked with others to design a mill to extract the copper at a rate generally considered impossible by other mining and milling experts. Their gamble paid off, and the men developed a fast-growing enterprise that mined and milled more copper than they had imagined was possible. Penrose's success in Utah encouraged him to invest and begin copper mining operations across the Southwest in Arizona, New Mexico, and Nevada. The works in Cripple Creek and Utah Copper generated an immense fortune for Penrose, which he brought with him to Colorado Springs, Colorado.