There are no roads into the Baliem Valley from the coast. Everything and everyone arrives by air, into Wamena Airport (WMX) at the south end of town. Flights operate from Jayapura (about an hour) and, less frequently, from Biak and Timika. Cargo planes share the airstrip; aircraft size varies from ATR turboprops to small Cessnas depending on the operator and the weather.
Book well in advance, reconfirm relentlessly, and build slack into your schedule — cancellations and delays for cloud or fog are routine. A Surat Jalan (police travel permit) for Papua is required and can be arranged in Jayapura, Sentani, or on arrival in Wamena. Bring multiple photocopies of your passport and the permit.