This study aims to determine whether Rangifer tarandus (caribou) antlers can be used as effective ecological indicators relative to other hard tissues such as bone and teeth using stable isotopes of oxygen, carbon, and nitrogen. Variation in the rate and timing of tissue development should create different stable isotope profiles for each tissue. Tissue from fifteen male specimens housed at the Canadian Museum of Nature were sampled. Stable isotope analysis was conducted along the length of the antler, on the third molar, and the mandible. Isotopic differences were found between the three tissues, with the carbonate carbon (δ13C) and collagen nitrogen (δ15N) isotopes showing significant patterns of variation along the length of antlers. Isotopic variation along the antler length is likely due to seasonal migration and dietary changes within the male caribou. These results demonstrate the potential for Rangifer tarandus (caribou) antlers to be used as ecological indicators.