I love mountain biking! I am basically obsessed with the activity, have been racing for half my life, and spend the majority of my disposable income on bike related activities. I would do it every single day if I could and at times I do.
There are a lot of places in the United States that get a lot of hype for mountain biking like Fruita, Colorado and Moab, Utah, and I love visiting these places, but if you live in the south then I would recommend stopping over in Albuquerque, New Mexico on your way out west. Yes, there are some great things about the ABQ besides "Breaking Bad"!
Just outside of Albuquerque is one of the coolest trails I have ever ridden called White Mesa. They call it White Mesa because of the gypsum that makes up most of the trail system. And gypsum makes for a great surface for single-track! Get ready to shred! It is also a paleontological experience because of the dinosaur bones sticking out of the eroded rocks here. There is also an amazing sinkhole at the top of one of the largest climbs on the trail. This place is hella cool! The geology here is amazing and the desert sky always sets a dramatic backdrop.
The trail is single-speed friendly and the climate is great year-round!
Although the trail is primarily geared towards mounting biking, hiking and horseback riding is welcomed here too. Don't forget your mountain bike on your next trip to ABQ!