HI Maddie.
I recommend a visit to the New Mexico Museum of Space History. http://www.nmspacemuseum.org/index.php
It is very close to White Sands. Very cool place.

You asked aboout White Sands. Definitely worth a hike (though the ability to sled down the dunes on waxed saucers is a bit overrated). If you are circling up in that area from Guadalupe NP you could do what we did over the course of a Spring Break: Guadalupe, Carlsbad, a stop in Lincoln NM (Billy the Kid town still well preserved), Cloudcroft (snowy ski town with some hiking nearby), White Sands, coming back down south through Las Cruces/Mesilla (Organ Mountains, beautiful hiking - Cool town).

Yes, we had high winds almost every day that March.

Spring break in 2010 is March 12-19th. There are always people at the peak. Mid-Late February might be your best bet.

Thanks to all for the replies. I'll be headed to Guadalupe April 9-10th. I wish now that I had booked in February, but I went with April instead as a birthday present to myself. We'll be hitting Carlsbad, Roswell (just to say we did), we'll hit that Billy the Kid town, and stop at White Sands and then Las Cruces before flying back. I'm psyched!

Awesome, thanks for the advice. Honestly, we're only staying in Roswell b/c I'm a Marriott rewards member, and I'll either get a free night there, or I'll get the points for it, I haven't decided yet. It was the only Marriott close to where we'll be, so I'll go for it. I'll check out Riudoso and see if we can work that in instead of either Lincoln, or perhaps Roswell entirely. How long does that peak you mentioned take?

I have hiked in all of the places mentioned above by Ric and I cannot disagree more strongly with his comment about Guadalupe Mountains National Park being a disappointment. It has it all: incredible beauty, great history, a variety of hiking opportunities, and wonderful solitude. The limited public access has kept the wilderness nearly pristine. The winds are usually at their worst in the spring (March thru June). Otherwise, the conditions tend to be variable but quite manageable.