From Coyhaique [1], the paved Carretera Austral is briefly contiguous with Ruta 240 to Puerto Aisén and Puerto Chacabuco [2], but after nine kilometers it becomes a gravel road veering northeast to Villa Ortega.
Ruta 240 continues west and, passing through the Túnel Farellón above the Río Simpson, it reaches the Viviana junction after 39 kilometers. Here, a smooth paved highway turns northeast up the Río Mañihuales valley and intersects the Carretera Austral about 13 kilometers southeast of Villa Mañihuales [3].
Heavy rains can and do cut the highway north to Chaitén [4], sometimes for several days.
Links:
[1] http://www.moon.com/destinations/chile/northern-patagonia/coyhaique
[2] http://www.moon.com/destinations/chile/northern-patagonia/puerto-chacabuco
[3] http://www.moon.com/destinations/chile/northern-patagonia/-northern-carretera-austral/villa-manihuales
[4] http://www.moon.com/destinations/chile/northern-patagonia/-northern-carretera-austral/chaiten