Walker, from Maple Ridge, B.C., and currently on the injured list with a groin strain, found the body while driving his all-terrain vehicle.
He then notified the Jefferson County Sheriff's Office.
According to sheriff's spokesperson Jacki Tallman, the body was in a wooded area near a trail on Walker's property.
Tallman added that Walker is not a suspect and the sheriff's office did not know if the person was killed at the site or if the body was dumped there.
Walker, 37, was injured during spring training while trying to check his swing. Walker is a three-time National League batting champion and hit .284 with 16 home runs and 79 runs batted in last season.
He also captured NL MVP honours in 1997.
The 15-year veteran played his first six seasons in Montreal before spending the past nine in Colorado.
For his career, Walker is a .314 hitter with 351 HRs and 1,212 RBIs.