If I complete a bachelor degree in mechanical engineering can i still become a structural engineer?

If i complete my mechanical engineering degree and say i decide i want to take the path of a structural engineer is that still possible? Because arent there some courses you do after you complete your degree to get accreditation?

What colleges/universities offer a degree in structural engineering in California?

I want to become a roller coaster designer and need a structural engineering or mechanical engineering degree. I live in the Bay Area California and prefer to go to college in my home state, but I will possibly go to an out of state college if it offered what I’m looking for in a degree. [...]