Mapsource (Garmin) has a 24,000 series for national parks west which includes Rainier and the grneral Topo series that covers the us in 125,000 resolution. For a gps I think the general series is all you really need. You used to be able to get them on Kazza but things are a bit tighter now. On rainier what you really care about are crevasses and they do not show up on either. You can mark your trail fine with the 125,000's.