East or west of the Andes ?

Planning to ride from Santiago to the bottom of South America starting the end of this December. I have about five months to do it, so I think that’ll be plenty of time.

Wondering if anyone has experience with this and can point me in the right direction. Part of me want to ride to Mendoza Argentina from Santiago then head south on the east side because there seems to be more dirt road options. I’d imagine less towns for resupply too..

I want to hop on to some routes in the mountains east of Los Angeles which seem accesible from the east side before making my way down to the carretera austral.

Any insight is appreciated.