Cochamó Valley sees 16,000 plus visitors per season. If you're looking for free camping, please consider another valley, including valleys to the north (Paso de Buriloche) or south (Valle del Manso). Previous to 2015, La Junta routinely exceeded its capacity due to mainly "free camping". Some details of this overuse included exposed feces, abandoned trash, 100s of fire pits, a social environment of excess alcohol, acid and screaming all night.
Today a huge local effort, lead by the Organización Valle Cochamó and the local government, implemented a control of the amount of people entering. During the high season, December through March, you must have a reservation to enter.
Land owners and tourist operators, furthermore, put in a tremendous amount of work towards their installations, trails, medias of education, etc. in an effort to better care for its waters, forests and mountains. We must be aware of the impact that too many of us can create.
Check out this article by Patagon Journal written back in 2016 that illustrated the severe problems the valley was encountering.
Cochamó Valley up to El Arco is private land and you need to have permission to camp. Respect the land owners and get permission before camping. Don't be one that ruins it for the rest. Be that one that spreads good practices and helps foment a healthy conscious of caring.