There are some alternative routes to where the normal route separates from Mike Dorse Direct (MDD).
The dotted blue lines indicates that the route is not visible, but behind a ridge for ex.
The one to the right is the most common, easiest, but also the longest from Arenal Camp.
About a hundred vertical meters below where the red line starts, there are some good places for camping.
The red line is MDD and goes straight up the left arm of the glacier, along a line directly towards the summit ridge of Ojos del Salado. It's steep in the end and be sure to be acclimatized before attempting to do rock climbing over 6700m. The normal route follows a rocky ridge to where it flattens out, it is switch-backing a bit on the plateau and also on the broad face leading up to the summit block.