We started out at the same place as yesterday but instead of going up the quebrada we climbed the steep, loose, rocky slope above the gas line to get onto the pediment.  It was a long hike up to the head of the quebrada where we had stopped the day before.  Matt went down with Rich to take a sample while I stayed on top and wrote yesterday’s entry.  Up to that point it was a fairly normal day but from there on it was like a marathon obstacle course.

Our first challenge came as we descended into the quebrada to the west, which looked to have excellent exposure.  We had to descend about 200 m down a very steep, loose, rocky slope.  At one point Matt and I crossed just above the crown of a large rock slide that had slid down a ~55° dip slope of sandstone.  We were at least 150 m above the Quebrada floor.  When we saw it later in the afternoon from the other side we realized how dangerous a position we had been in.  A slip there would have been fatal.

Sampling in the quebrada was excellent but we soon found ourselves in an area of sculpted sandstone dry waterfalls.  The first one had a pool at the base covered with a thin layer of ice.  Matt managed to climb above and around it.  I, in my stubborn way, chimneyed down to it thinking I could use the sandstone just above the water to spring across the narrow pool.  To my dismay, the sandstone was slick with loose sand so my plan wouldn’t work.  I was also too far down to climb back up.  My only alternative was to get my feet wet.  I slid into the pool, breaking the ice.  To my great surprise, the pool was nearly chest deep!  It was cold!  I bounced over to the other side where Matt grabbed my arm and yanked me out.  The cool, dry wind that had been pounding us all day gave me the chills at first but also dried me out within 20 minutes.
 

Here I am, wedged in the sandstone above the pool at the waterfall base.  At this point I think I still really thought that I was going to make it  over the black plunge pool below me  without getting my feet wet. Note the  slight reflection in the pool. That's ice; the whole pool was covered with it.  (Photo by Matt Bourke)

A few minutes later, we discovered there was an impassable waterfall just beyond our next site.  Rich and Brian tried rolling boulders into it hoping one would wedge and provide a footing for a descent. I was rather relieved when that didn't work. The only possible way around the fall was to backtrack and climb up the west wall.  It was rough going.  When we reached the top, it was obvious that we were done sampling for the day.  Not only was it 4:00 but the pediment surface was deeply incised below us and many sandstone walls were present.  Impassable falls certainly were within.  We decided that the sampling season was over.
 

The scale of this photo is large! The quebrada is more than 100 m deep and the slopes on the far side are very steep. We hiked up to the head of the arroyo and the down the pediment surface on the far side. Although it was an arduous day, it was spectacular throughout.

Our next task was to get back to the vehicle in the remaining 3 hours of daylight.  We had two options: 1) descend into the quebrada and climb the very steep far wall or 2) walk up the long gentler slope on our side to the head of the quebrada and then walk down the pediment surface on the opposite side.  No longer feeling like mountain goats, we opted for the latter.  The hike up was 2-3 km long and took about an hour.  Matt checked our elevation when we got there.  It was 3986 m or 13,100’.

From there we had a gradual 4-5 km descent to our waiting vehicle.  We interupted it once to roll some boulders down into the quebrada.  We had some spectacular bouncing rolls!  The worst part of the descent was the last 100 m.  By then the sun had set and we were walking under the moonlight of a moon at first quarter.

We left the field and headed for Humahuaca.  Pedro drove like a bat out of hell, making it in an hour.  I remember when I started work in the Andes, in 1984, I had a fear of driving on one-lane, steep-sided, mountain, dirt roads.  I had total confidence in Pedro’s night driving so I just sat back and enjoyed it, dozing off for awhile. 

We got rooms at the Residential Humahuaca and took our first shower in 5 days.  It felt great in spite of the lukewarm water temperature. Dinner was eaten at the bus terminal again.  We were hassled by a drunk for awhile but the manager called a cop who dragged the guy away.

We returned to the hotel and stood by the fireplace for a few minutes before going to bed.  I was already starting to feel a full body ache but sleep overcame me quickly before I could dwell on it.