https://www.acs.org/education/students/highschool/olympiad.html

This is USNCO Semis, if you are looking for alternate phrasing. I didn't really study (AP Chem only). I live in a really competitive region (please no doxxing me in comments). Apparently Science contests aren't a thing in Manifold so Competition Math it is... Also, I won't bet here apart from when I get my results, to recoup startup costs.