Find US Races  

While there are several methods to search for specific distance races in specific locations, I have found Running In the USA to be an outstanding site for searching and learning about races of all distances, across all states in the US.  They also provide easy links to the actual race websites, and they cater to people attempting to perform goals such as running a race in every state.  This is an excellent site for anyone searching for local races, and especially for persons searching to run in many states, as a great way to view many parts of the US.