When I was a teenager, we would wake up on a summer Saturday in country A, drive through the entirety of country B, and stop by in a lovely city in country C, all in 76km. With full double border crossings, changes in climate and culture and population, several different terrain types including some proper big mountains, and everything :)

Point is, yes USA is huge (let alone Australia) and skews our sense of distance, but 100 miles is not as trivial distance as we sometimes instinctively feel :-)