The easiest way to get to White Sands National Monument is to drive north on I-10 West to US-70 East from El Paso, Texas towards Alamogordo, New Mexico and the Holloman Air Force Base. The drive should take between one-and-a-half and two hours.
Coming from the north, the closest major city is Albuquerque, New Mexico; take I-25 South to US-380 East, and then US-54 West. The drive from the north is less direct, and is a minimum of three-and-a-half hours. However, coming from the north awards the chance to stop in Carrizozo, New Mexico, an artistic commune town complete with a quaint store front downtown.
White Sands National Monument offers a wealth of riches. There are innumerable activities to partake in within the park, ranging from moonrise guided walks to backcountry camping to sledding down the dunes. A full range of activities can be found at the monument's webpage.
As the White Sands National Monument is close to the White Sands Missile Range, traffic to the monument is regularly closed for up to three hours during tests. In general, tests are scheduled two weeks in advance, and a testing schedule can be found here.
Even in mid-October, the beating sun shone off of the dunes with such ferocity that it was as if the ground itself was another star. But instead of flaming hot, this terrestrial-based star was gorgeously cool to the touch and silkily smooth.
With the sky overhead so blue that it bordered on a whitish powder, and the silent sprawl of the gypsum dunes blanketed out to the horizons like clouds rising from the ground, White Sands National Monument is an alien landscape in the middle of nowhere; El Paso is the closest city at a mile and a half away.
But despite, or maybe because of, the distance, White Sands is a wonder to behold. As the dunes roll seemingly out to the mountainous horizon, all perspective, color, and sound becomes amplified and distorted in a sense of wonder. With nothing to absorb sound, the merest whisper reverberates far over the neighboring dunes, making the sounds of children sledding down the gypsum sides an unknowable distance away sound as if they were within arm's reach.
Unknowable distance away because, like sound, all orientation is lost out in the dunes. Uncompromisingly pure, aside from the spattering of stunted scrub and one magnificent yellow tree that looks straight out of Game of Thrones or Lord of the Rings, the sands stretch unperturbed and without scale. Running out to the tree, or attempting to, was a quick lesson in visual failings, as no matter how far we ran we appeared to get no closer to it ... until we were suddenly underneath its branches.
In short, the White Sands is a mind-fuck. The most gorgeous, unexplainable, natural mind-fuck around.
Just remember what a ranger told us before we ventured out of our car into the dunes, barefoot and without water:
Keep a reference point on the horizon, since it's easy to lose your way out in the sands.