The dunes cover an area of about 30 sq miles.

The ranger told us that the tallest dune “Star Dune” was 755’ tall. I said no problem. She said you are at 8500 ft so keep that in mind. Ha! Breathing was hard almost immediately. We made it half way and the sand storm started. The final stretch was like 60 minutes in on a stair-master. When I reached in my pack Caiti was “thrilled” that id forgotten the water but had a nice warm can of beer.

Maps of Great Sand Dunes

This is a good overview of the park.