If you're interested in Stott Pilates certification in Utah, then visit Intermountain Pilates Training Center in Salt Lake City. They have trainings scheduled for April of this year and they not only offer extensive mat training, but they delve into Pilates for injuries and prenatal participants.
FiTour is another organization offering Pilates certifications (which is where I received my Mat training) for very reasonable prices. The textbook is a great resource to have and I refer to mine often for my classes. FiTour also does Yoga certs so be sure to check them out for that as well.
Powder Blue Productions is another great organization (where I received my PiYo training) and they have a lot of certs available in Utah. Certifications are held in Tremonton, Taylorsville and St. George, so it's a pretty good spread. I loved training with Michelle and still use cues that she taught us during that workshop.
I trained for Yoga via YogaFit, which has an aerobic approach to Yoga instruction. It was a two-day cert when I participated and even 4 months pregnant I had a great time. They have a lot of trainings scheduled for 2011 that you should definitely consider. Like Stott Pilates, YogaFit offers certs with specific concentrations, such as for seniors or those with back concerns.