The TCH calves and summers in the National Petroleum Reserve in Alaska (NPRA; managed by the BLM) on Alaskas North Slope. The TCH is the most important caribou herd for subsistence in villages within the NPRA, but it is currently in what appears to be a steep population decline. This will have significant adverse impacts on the social well-being of many NPRA residents. We need to continually update our knowledge of TCH range use and subsistence harvest in order to best manage this important population and to prevent any adverse consequences to the herd from BLMĂ‚Âżs management of oil and gas resources in the NPRA. Since 1991 the BLM has been working cooperatively with the Alaska Department of Fish and Game (ADFG) and the North Slope Borough Department of Wildlife Management to monitor the herd, sharing resources and data to accomplish a large task in a very harsh and remote environment. During that time, the BLM has entered into various cooperative agreements with each of these entities to accomplish multiple monitoring objectives. One of the most important and expensive tasks over that time has been to maintain a reasonable sample size of satellite-collared animals to be able to describe the TCHĂ‚Âżs seasonal use ranges with adequate confidence to appropriately manage activities the BLM permits. We have also cooperated on studies of herd body condition and health and calf survival. At this time the BLM needs to make a renewed contribution to the cost maintaining satellite collars.