Why is Oregon State University not on your list? Like U Minnesota it’s a large state university. The Math and Sciences at OSU have a strong reputation. Yes, the classes can be quite large in the first couple of years but once you get into the heart of your major I expect that the classes sizes are much smaller, particularly in Math and Science.
Texas (Austin) and Univ. of Washington.
Take as much advanced math as you can before applying. Show your passion and exhaust all available math resources. Good luck.
Oregon State is on my list as an in state option.