Hopefully today would not be that day. We rode a bus for several sleepy hours and then started our hike at about 14,700ft, which was already the highest elevation I'd ever achieved. My $2 hat from Otavalo came in handy.
Finally we reached the highest point we could hike to; 16,400ft! To go further on the glacier would require ice climbing equipment, and also a day of acclimatization to be able to handle 19,000ft. I'd like to have done that, but, so little time.
We descended back to the refuge, where a fantastic spread of food awaited a dozen hungry hikers.
After hiking the rest of the way down to the parking lot, we jumped on mountain bikes and barrelled down the dirt road out of the park.
I recommend Gulliver Travel for this tour. At $35 I thought it was a good value, they provided a good English speaking guide, good food, no problems. The easiest way to book a tour is just to turn up at their office in La Mariscal, see what they have available and sign on.
The vegetation at 12,000ft looked remarkable similar to what you'd see in Colorado at a similar elevation.