There is no national ferry authority in the United States, and that single fact shapes everything on this site. A crossing may answer to a state DOT, to a county highway department, to a township, to a non-profit run by volunteers, or to a family company in its fifth generation. Each publishes differently, or does not publish at all.
So nothing here is aggregated from a database. Every schedule and every fare is read off the operator's or the agency's own publication — a web page, a PDF, sometimes a JPEG of a printed table — and the date it was read is printed beside it. Where the source is an image, somebody looked at the image.
The rule when two official sources disagree is to publish neither figure and say so on the page. It happens more than you would think: an operator's marketing line contradicting its own timetable, a schedule page listing dates that fall on the wrong weekday, a fare row priced identically one way and round trip. A missing number is honest. An invented one would not be.
Every page carries a next-check date and is researched again before it passes. Even then, a boat can be pulled for repairs, ice or weather on the morning you travel, and only the operator will know that. Lauttainfo USA sells no tickets, takes no commission and is not connected to any ferry company; the site is paid for by advertising.