There are many federal frequency resources available across the Internet. 
If you have some web sites or email lists that you find helpful, pass them along and I will post them here.

My monthly column, Federal Wavelengths, appears the in the e-magazine The Spectrum Monitor.

My Fed Files Blog is updated often with frequencies from across the 
country and can be found here:

The long running Fedcom email list from

A good source of frequency information in southern California is the SoCal Fedcom Blog:

The Radio Reference Forums, Federal Monitoring Forum: