Visited for the first time yesterday with my boys. Such a fun park to explore! Rangers and volunteers are knowledgeable and friendly and the scenery and rock formations are beautiful. Going back next weekend for the guided cave tour!
Not a difficult trail, the views are beautiful. We went there one Saturday, they had one little festival and they formed groups with a guide who explained the different areas. It is ideal to visit it with the family. We did two trails, one to the left of the visit center by Chain Trail (2.2 ml) and another to the right near the road around the mountain (2.0 ml). When is not open for the public, you have to call in advance and request permission to visit.
I have been going to Hueco Tanks since childhood- when you could go anywhere. Even though only a portion of the park is open to the public, there is still plenty to do or see. The day can easily be spent exploring all the various huecos & caves or just rock climbing. You get a real sense of history here & despite the amount of people, it is still pretty serene. Lots of birds & squirrels. There is plenty of smooth rock if you're inclined to sprint up to the top & excellent hand & footholds everywhere, so you can sprint to the top or test your climbing abilities. In fact, the park is pretty much solid rock in the middle of the desert. You can also plan outings w/ the rangers to see all the closed off cave art too. With the exception of a few huecos & the picnic areas, there isn't much shade so plan accordingly.