C.R.S. § 30-10-504

The sheriff of each county, as soon as may be after entering upon the duties of his office, shall appoint some proper person undersheriff of said county, who shall also be a general deputy, to serve during the pleasure of the sheriff. As often as a vacancy occurs in the office of such undersheriff, or he becomes incapable of executing the same, another shall in like manner be appointed in his place.