I've worked for a fair number of high profile startups in Chicago and I've seen a number of people reach the 300k+ realm.
Generally these people have been highly skilled directors, executives, or principle engineers and they have an exceptional track record of delivering results. In general I would estimate most of the ones I have worked with as having 10-20 years experience and I believe they got to where they are by having a great combination of raw talent, a great personality, drive, and the ability to coach and mentor others.
Note that I have also come across at least two or three people at this level that had gotten there simply by being friends with a founder or early investor. Usually these types of people don't last more than a year or two though. Once the company starts gaining traction and brings in real leaders that expect real returns these types of individuals are usually the first to go.
Also in Chicago the principle engineers that I have seen hit this level tend to have a strong understanding of stream processing, real time analytics, the smack stack, systems engineering, and data science. From my own interviewing and hiring experiences in Chicago I can also say that if you can demonstrate skills in these areas as en engineer and have some greenfield experience it's pretty easy to hit 150k-200k total comp with no more than 5 years of total experience. I haven't seen anyone under principle hit 200k+ with a reasonable work life balance, I know a few fintech engineers that approach 250k+ but they work 80 hour weeks and hate their life.