If the races are USATF certified, there should be no problem with using the logo. Your friend may want to include the USATF course number as well.
However, the logo should not appear on any part of the site that is not directly related to the certified course, or be used to imply a relationship with USATF.
While I am the Course Registrar, I have no legal authority concerning the use of the logo. This is only my personal opinion, and you know what they say about those.