Tribes Served Assiniboine and Sioux Tribes Our Staff Denni GarfieldFiduciary Trust OfficerPhone: 406-790-9858 Matthew KingsburyAccounting TechnicianCell: 406-514-0977Office: 406-768-3288 Mailing Address Bureau of Trust Funds AdministrationAttn: Fort Peck AgencyP.O. Box 26928Albuquerque, NM 87125 Office Location Fort Peck AgencyMedicine Bear Complex500 Medicine Bear RdPoplar, MT 59255Fax: 406-768-3289 Directions to the Office Off HWY 2 Turn RIGHT at flashing yellow light onto KIRN RD, turn LEFT at Medicine Bear sign, agency is on right side of road. Off HWY 2 Turn LEFT at Spotted Bull Treatment Center, turn RIGHT at Medicine Bear sign, agency is on left side of road. Unclaimed Money BTFA currently holds $80 million in trust for thousands of beneficiaries with no known address. Search our records to see if your name, or the name of someone you know, is on the list.