<p>zephyravatar, the only other one I know of is ARML, a math team tournament held each June. There are one or two Canadian teams who go, but their selection criteria may be fairly strict, and you would also have to live in the right region. It’s pretty high-level, as it’s basically the national/North American championship tournament. If you’re interested, ask around on AoPS (link above) about how to join or try out for the team.</p>
<p>The nice thing about ARML is that if you don’t live in a region that has a team, you can form your own and travel to the tournament, as long as you can find 14 other like-minded students and the funding to get there.</p>