What type of organization is the League of California Cities?

Is it a corporation? What is it? I went to the IRS website and looked at the list of nonprofits and the League isn't on it. I can't figure out what it is, and would be really grateful to anyone who can tell me. Here is some info, maybe you'll have better luck than me: http://www.cacities.org 916 658-8200

Public Comments

1. sounds like a team of super-heroes.
2. Sounds like the SPP...
3. corp
4. It is a Voluntary and Non-Binding "Think Tank" type organization. To share common problems and information from other cities, and to suggest and perhaps lobby for solutions as a whole.