In Afghanistan river bottoms are the best routes for travel most of the year, given the lack of roads. The photo seems to show the photographer, given the clothes and backpack, with his guide and mule, taking a rest break.
Here's a photo by Luke Powell
http://www.lukepowell.com/ , with a few of his comments below it:
"In the 1970's, on most maps of Afghanistan showed a road which made a great circle around the country with roads that radiate from this ring to Meshed, Peshawer, Quetta, and points in Soviet Turkestan, Uzbekistan, and the Tadjik S.S.R. Much of this circle of roads was hard surface highway built during the 1960's by the United States and the Soviet Union. The American-built stretches were very much like a minor secondary road in the United States, narrow asphalt that was thin enough to be in need of frequent repair; the Soviet-built parts were concrete, three lanes wide and a meter deep, solid enough for tanks. However, the northern route from Shebergan to just northeast of Herat, while shown on most maps, did not in fact exist. This is what the northern route was like. It was a trail for fourwheel vehicles only, and it was impassable for many weeks of the year. This was still the case when I returned in 2003."