Aug 19 early pm

Early afternoon on the 19th we checked in to our motel in Alamosa and then went out to the Sand Dunes National Park.

The first image is the entrance to the dune area. I walked about to the base of the high dunes but to the right quite a bit to where the high dunes were just beginning.

The second image is of the dunes in the foreground and the mountains in the background.

The third and fourth images were taken from a grassy area of the dunes.

Although the temperature on the dunes can get to 130F, this day was actually quite cool (in the 60s of 70sF) as a rain storm had just come through.

The sand comes, according to accepted theory, from the San Juan mountains 60 miles to the west (which are plainly visible from the base of the Sangre de Cristo mountains or from the dune area or from anywhere in the San Luis Valley).

The National Park site gives lot of information on this here.

The age of the sand dunes is less certain (see q&A couplet 13 here)