The key piece of language from the act is using Smokey’s image or name “knowingly and for profit,” which at least grants some slack for non-commercial usage - but not much.

This document (pdf), inocuously entitled “Smokey Bear Guidlines”, is an amazing read.

There’s far too much brilliance to quote here, but among my favorites were the instructions for how to behave while wearing an authorized Smokey Bear costume, including:

“Express sincerity and interest in the appearance by moving paws, head, and legs.”

and

“The costumed bear should not force itself on anyone. Do not walk rapidly toward
small children.”

Wow, no wonder we give so much money to the government. That is one thorough document.

Costume
…
Examples of inappropriate uses are: Christmas parties, summer picnics, Halloween parties, Job Fairs, the Combined Federal Campaign, or any situation that might compromise Smokey’s integrity or give the appearance of impropriety.

There goes my Halloween plans.

Whoa, he’s got his own dot com just for licensing:
http://www.smokeybearlicensing.com/

And as if there was any lingering doubt about how serious this all is:
The Official Smokey Bear Style Guide (pdf)

Rule #4.0
Clearspace: Use Smokey Bear’s hat as a guideline