This a good Mountain to visit it is located on Santa Catarina county, the problem is that is not well know route to get there, You have two options to get there one is staring at La Huasteca on the way to "Rompepicos", and the second is starting at San José de los Nuncios wich is the route I took.
The route I did is starting from San José de los Nuncios, I drove from Monterrey to Saltillo, next to the entrance to the toll road to Matehuala (México city) take a return to Monterrey, 300 meters ahead theres a not paved road to San José de Los Nuncios, this road cross above the toll road to Matehuala, you drive 3 kms aprox to San José de los Nuncios, there you have to ask for the key of the gate that give you access to the road to Llanitos.
Llanitos is a little "ejido" with few houses there. It is located on the base of the Mountain, From San José de los Nuncios is about 34 kms inside the canyons, the road starts very dry but when you get to the canyon turns very green with a lot of pine trees.
José Valdez can tell you where to start hiking to the summit.
No fees are required, you just keep clean the place and ask for permission to cross private property.
You can camp there, you just have to find a good spot to do it, but there are enough places you can do it.
Please don´t fire or if you have to.... be careful about the way you do it.
The best time to climb I think is on from November to March, on summer is very hot and dry.
I´m attaching a google earth image with the route we did to reach summit, this tracklog was created with a Garmin Etrex Legend C