Aviador Carlos Campos Airport, usually called Chapelco Airport, sits between San Martín de los Andes and Junín de los Andes. Flights are seasonal and weather can interfere, so many travellers also use Bariloche's larger airport and continue by bus or car.
By road, the classic approach is the Seven Lakes route from Bariloche via Villa La Angostura. Buses also connect San Martín with Junín de los Andes, Neuquén city, and other Patagonian towns.