CHSAA
Colorado High Schools Activity Association.
Governing body for athletics, music and speech activities for Colorado Schools

Colorado Bandmasters Association
The CBA offers marching band competition for its membership.

Marching.com
Source for scores from high school marching band competitions, a calendar of parade and field contests, and a directory of links to marching bands on the net.

Marching Band - Wikipedia
Encyclopedic article on the history of marching bands. Offers types of bands, performance elements, and a list of the top bands in the U.S.

John Philip Sousa: American Composer, Conductor & Patriot
Collected works of the "March King" - includes sound clips, book reviews, pictures and more.