1 spot in North America.
Some stretches of dirt don't just get ridden — they teach the language everyone else borrows. A-Line is where a whole generation first understood what 'flow' means. You ride the Fitzsimmons up without turning a pedal, and what waits at the top is a shaped run of tabletops and berms built to keep your hand off the brake. It wears a black rating, but 'approachable flow' and 'black with mandatory drops' both live on the same line — which one you meet depends on how much speed you're willing to carry. It opens in pieces: the park splits it into zones that don't always run together. You earn it by chairlift, not by climb.