What is going to kill the most people is radionuclides, when you eat it, drink it or breath it in. The time frame is from 1 day to 40 years. The explosion does a lot of immediate damage, but the fallout will kill long after the blast. If you survive the initial blast effects, you will need a good gas mask and a way to escape the area. If it was a neutron bomb and you are near the blast, you will probably die that week. To survive after the explosion, you need a gas mask, a geiger counter & sealed food and water sources. Then you have to move to a non radioactive location. I don't think there is a safe place in Colorado. We have too many command centers and nuclear missiles in silos. The weather will spread the fallout everywhere. Best evacuation bet is a non-nuclear state south of the border.

http://www.cs.amedd.army.mil/borden/...8-022839410685