Wilderness fire managers are often confronted with natural fire ignitions that start and/or burn near an adjoining agency's wilderness area boundary. Management strategies for prescribed natural fires (PNF) are often developed using the adjoining agency's wilderness boundary as the maximum allowable perimeter (control line) for the PNF. When this occurs, fire's natural role in the wilderness ecosystem may be restricted. The difficulty of burning near another agency's jurisdictional boundary can be overcome by strong planning, close communications, and timely coordination between the two affected agencies. Communications and coordination can be achieved only through developing and maintaining a strong working relationship with the fire manager of the adjoining agency. Keys to good interagency coordination are (1) investing time, (2) understanding the policies and procedures of the adjoining agency, (3) developing and maintaining open communications, and (4) having a commitment to see it succeed.