It's only about a mile horizontally to reach this summit, so perhaps 1.4 mile on the ground, but it tends to take over an hour to reach this spot, since you lose much of your upward and forward progress on each step to the loose sand. I describe these sand dunes in four pages of my 320-page guidebook, "Photographing California Vol. 2 - South".
To emphasize the subject, I set the aperture for this 70mm shot to the maximum the lens would deliver, f/4, to minimize depth of field and soften and the background. shooting at ISO 200, the shutter speed ended up at 1/1250 second.
Sometimes in life's explorations, you find a scene with such scale, grandeur and impact compared to everything that you've experienced before, you're literally stopped in your tracks.