400 feet seems short, unless it was “never sleep more than 400 feet from their method of arrival” or similar. Even a short walk down a path will quickly go past 400 feet.
But maybe you can drive right into Old Faithful; I’ve never been.
But maybe you can drive right into Old Faithful; I’ve never been.
Technically, it's about 600 ft. from the parking lot, but half of that is the distance from the viewing area to the geyser (you never actually walk right up to the geysers, you always want to see them from a bit of a distance).
From what I remember of Yellowstone (it has been two decades since I visited), it's a national park where pretty much everything is pretty damn close to roadside, as the roads are designed to take you by all the interesting things.
The Grand Canyon is my favorite example. The rim by the visitor center can be packed but once you're a half mile down one of the trails you won't see a soul.
For those who naturally wander, it can be hard to understand. But a lot of visitors barely leave parking lots and pull-outs. I don't know about 95%, but I've definitely noticed this at my favorite California parks.
The road-bound will take pictures at the scenic viewpoint on the shoulder of the road and at various entrance signs, and maybe use the restrooms. Then they pile back into the car to go to the next pull-out, restaurant, or hotel parking lot on their itinerary...