Being a child of the Southwest there are two times each day you press pause for, sun rise and sunset. Such is so in my personal opinion for best viewing Monument Valley. The National park conveniently opens at 6 am and closes at 8 pm from May through September. Fantastic views from every direction. What especially makes this National park unique is the 17 mile scenic driving path. This easy going feature will let you make the most of the experience getting in all the photos of that beautiful sunrise or sunset you want. Hikers also have many paths to choose from and more miles to experience unique features that aren't visible by car.