The federal government has employer locator.
Look for the Career Tools item in the menu on the left of the page. Follow directions to locate the industry, occupation, county, etc. Choose a 5-mile radius because it includes businesses outside of that range and a 10-mile radius will give you hundreds of listings from all over the county.
It is important to know the employers in the industry you want to work. Check out the following links to websites that compile a variety of business listings.
www.idealist.com Search through an international directory of nonprofit and community organizations.
www.hoovers.com Provides industry information, as well as information on private, public, IPO, and non-U.S. companies.
www.vault.com Search companies by industry, location, size and revenue.