Done the St George Marathon twice. St George is a bit more than 2 hours north of Las Vegas near Zion National Park. I plan to run it in 2011. Registration for the lottery is April 1st-May1st. My Boston Marathon qualifier for 2011 was at the 2009 St George Marathon. Incredibly well organized "local event" with all the attention and care of the big city marathons. Voted Best Organized Marathon in the January 2010 Runner's World and I agree! Total mobilization of the community to put on a great event. Make sure you go to the pasta dinner. The grannies volunteering to help clear the tables are fantastic!
St George is a point to point course. You start in the dark way out in the desert after staying warm by dozens of huge bonfires. First half is relatively hilly, all downhill through mile 7 and then all uphill mile seven through 11 including the one mile steep ascent of the Veyo volcano. Second half is all downhill into St. George for a net negative 2500 feet from a start at 5000 feet. The red rock scenery is spectacular especially in the second half as you plunge down Snow Canyon towards town.
Well done YouTube video by the race organizers here. Course overview starts at 2:30.
Great essay by my friend Fasteddie Knapp about what the start feels like. Fe, as he is known, has run 15 St. George Marathons.