Altar Reto Trail was one of the hardest and coldest races of my life. I ran it in 2025 in the mountains around Quimiag, and my watch recorded 44 km in total. One memory explains that day especially well: it took me more than five hours to cover 20 km in the mountains. I am not using those 20 km as the race’s total distance; that is the section I associate with the effort and the mud.
The mud was knee-deep. It was not a short obstacle but a constant condition that made movement difficult. Every step cost something and progress became very slow. After those 20 km, they hosed us down. That scene says a lot about how we arrived at that point in the race.
At one aid station I drank coffee at altitude. Thirty meters after leaving the station, I threw up. I remember it as a specific anecdote from that day, without turning it into a general rule about coffee or altitude.
I did not see Laguna Negra either. I do remember an extremely windy ridge. I assume we were around 4,000 m there, but that altitude is my personal estimate, not a confirmed course fact.
This is my experience of the 2025 edition. The 44 km record comes from my watch, while the 20 km reference describes only that mountain section; this is not an official guide to distance, elevation or conditions.