USA Track can be found online here
http://www.standardgaugetrack.com/
And it's worth every penny. I had some of the MTH track (note I'm a huge MTH fan) and it was complete garbage. Shorted out all over the place, was a pain to put together and never sat flat on the table. The USA track is top notch, easy to assemble and never gave me any problems.
Thanks,
Sam