Access to the base station by car is by three routes, each culminating with the upper portion of the dead-end Cog Base Road. The advertised, roughly eastbound route uses the Base Road's full length from Bretton Woods. An especially scenic route, initially southbound from U.S. Route 2, follows Jefferson Notch Road, a narrow dirt road with hairpin turns; it rises to the pass, at above sea level, between Mount Jefferson in the Presidential Range and Mount Dartmouth, before descending to its junction with the Base Road. The Jefferson Notch Road is closed to wheeled vehicles in winter - and usually before and after - and used primarily by snowmobiles. The roughly northbound route from U.S. Route 302 in Crawford Notch via Mt. Clinton Road is also closed in the winter to vehicular traffic. Operations of trains all winter began in 2004-2005, and the Cog Base Road is plowed and sanded all winter to allow tourists, skiers, and employees access to the Base Station.