Hi, I would like to reserve a night in a yurt...any ideas if there's a website or a phone number for Gegentala yurts?

Hi, you can take a bus to Siziwang Banner (Si Zi Wang Banner) at Hohhot Bus Station. Upon your arrival, the Gegentala is around 30km away. Then you can take a taxi or rent a car to reach easily.

I have no idea about the contact or website of the G yurts. But it is suggested to have a local people or tour guide as company. Upon arrival, he or she will help you to arrange one night stay in yurt.