Because it has been around so long, the majority of it's area is covered by large Cottonwood trees, which provide shade, and benches for short rests.
The fair grounds are approximately a mile square. The New Mexico state Fair is one of the largest in the country.
(Separate tickets!) Two I know of this year are Randy Travis, and Creedence Clearwater Revisited. Pretty exciting! :-) There are also usually entertainers following the rodeo events. It would include events such as bull riding, bronc riding, cattle roping, barrel racing, etc. This is a pretty big event in the world of American rodeo. If you have never been to a rodeo, I think it would be an entertaining addition to your visit to the Southwestern U.S. I just returned from a visit to the Expo New Mexico/ State Fair website, and have to agree with you, that at this time it is very lacking in 'specific' information.