Below you will find links to most useful sites that have directories of shelters. Please remember that although places may list themselves as dog or cat shelters they are often presented with other little critters that are in need of a loving home so be sure and give them a call.
Hugs 4 Animals
Hugs 4 Animals provides a very comprehensive list of rescue centres in the USA . They are listed by individual states and postal codes so you are bound to find one in your area.
Doxies World also has a good listing of recue centres.
For dogs go to...
For Cats go to...