I actually used to spend quite a bit of time up there; my Eagle Scout project was the trail from the visitor center to La Cueva, and my little brother's project was installing some concrete steps up by the spring itself. Surprisingly, the trail and steps were still intact, and I never actually made it all the way up to the springs before, nor off to the resort,, so this was a pleasant mix of revisiting old ground and seeing new things.
I have a few picture galleries up:
And I got around to processing the GPS track I took:
It's an older unit (a Garmin eTrex Vista), and it tended to lose signal whenever I wasn't holding it out in front of me (hence the jitters up by the springs), but it was still amusing.
Final stats? Just barely shy of 10km walked, with some 420m total vertical climb in there (parking lot was at about 1730m, highest point was 1920m). Took us about 4 hours.
I got a little sunburned, and my legs felt it the next day, but it was very much worth it; a lovely afternoon in a lovely area with some lovely friends.