I'm a natural (coding since 3rd grade), out of college for 6 years, and I've only known 1 engineer in my career who made over 200k. Now if by BigCo you mean Facebook, Google, Apple, Amazon, then I don't know them, so I can't comment.
But if by BigCo you mean IBM, Cisco, Intel, etc then I can guarantee you that I don't know a single person making 250k, and glassdoor generally corroborates (if you google STAFF (> senior) software engineer in SF for IBM your average is 132 base in SF)