recommendations for trip to Sierra Gorda without a car

[mr bill]

Megan, I think your trip and time frame are maybe too ambitious. The Sierra Gorda make the mountains around GTO seem like ant hills.
If you had a car it would be a minimum of 5 hours [see SCT Traza su Ruta] but probably more. In the 2-3 times I've driven to Jalpan I always seem to arrive in late afternoon. By bus you'd have to go from here to QRO and find a connection to Jalpan
On Primera Plus you could travel
08:00 LOCAL 1 10:30 but after that I'm blind as I do not know which company goes to Jalpan - correct that PP does:
12:00 LOCAL 2 15:15 and then you'd have to find a way to get to your eco-lodge.

If you can try to give yourself 2-3 days extra time. Its great country and the missions are interesting. I've gone up there with my mountain bike and used Jalpan as a base to visit a couple of the nearby missions and then driven to the others as well as Las Pozas the Edward James site