Cerro Lopez is a 2076m mountain on the Circuito Chico near Barriloche. It's easily reached by collectivo which drops off near the turn off to Colonia Suiza.
The trail itself is a very steep 8km climb, first to Roca Negra and then on to refugio Lopez at the top.
The trail to Roca Negra is very steep but we'll marked and takes around 2 hours to complete. On the way there are waterfalls and stunning views of the lakes and mountains.
Once you reach Roca Negra, there are even more stunning views and a place to rest and have some lunch before tackling the next part of the trail to refugio Lopez.
The steep trail to Refugio Lopez takes around and hour of solid trekking up the mountain.
You can descend via the road from refugio Lopez which, although longer, is a much easier climb down and conveniently ends at the bus stop at Colonia Suiza. In total this trail takes around 6 hours with stops, but ultimately us quite an easy and rewarding day trek.