Bring lots of water, sunscreen, and potentially an umbrella. Don't bring your pets.
Start in the parking lot. Once you cross the creek, you'll need to look for the tallest dune you can see. It should be right in front of you. Work your way up to the top of High Dune
. It is best to zig zag, or switchback so you do not get overly exhausted. Now remember that there is no real trail, it is all sand, so don't get lost.
Once on top of High Dune
, follow the ridge down to the SW, and after a little ways you'll need to do some switchbacks down into a little valley. After that, you'll start a the climb up to Star Dune
. This climb is also steeper, so use switchbacks.
Once on top of Star Dune
, you can follow its northern arm out, and then branch off to the east. Just follow the sand field to the NE, and try to stay on flatter ground. After a ways (6.2 miles), you'll come between two dunes, after this is your ascent of Highest Dune. Switchback your way up this one also. Highest Dune is much higher then Star Dune
, or High Dune
. This is only because it sits at a much higher elevation (2,650+ feet), but the actual sand portion is smaller.
To return, just head back the way you came.
Sand. Sand. Sand.
The Great Sand Dunes have formed over thousands of years, that is the speculation at least. No one is quite sure because there is no good way to date sand.