How did they know????

Just checking out my new camera, a Nikon D3300.  Jumping from 6MP to 24MP is sort of like switching from a Geo Tracker to a Ferrari, I think.  It arrived yesterday afternoon, and I'm excited about getting back into some close-up nature photography.  But, on this first day, I just shot random items to check on resolution and other factors.  The above statement was on a USFS map at the beginning of the South Park trailhead.