Carretera Austral: the Chilean road
What Chile's Carretera Austral is, what the road is like, and what crossing from Argentina into another country means in general.
General travel guide. It does not describe rental terms.
It is a road in Chile
The Carretera Austral is Chile's Route 7. It starts around Puerto Montt and runs south through the Aysén region, past towns such as Chaitén, Coyhaique, Cerro Castillo, and Puerto Río Tranquilo. It is not a piece of Route 40 and it is not an Argentine road.
The landscape is fjords, temperate forest, lakes, and hanging glaciers. The marble caves sit near Puerto Río Tranquilo, on General Carrera Lake.
Pavement, gravel, and ferries
The road is not continuous pavement. There are paved stretches, long gravel sections, and, in the north, crossings made by ferry. Those boat schedules change with the season and the weather.
Most people drive it from spring into autumn, roughly November to April, when more services are open. In winter several stretches and crossings get difficult.
A border is another country
Reaching it from Argentina means leaving the country. That is a migration and customs process with the authorities on each side, not the same as driving inside Argentina.
This guide does not say whether a rental allows that crossing, or which permit, insurance, or notice a company asks for. If the trip includes Chile, ask that separately.