Stapleton was still east of Denver. I think the siting of DIA was probably more that there was a bunch of flat relatively empty land even further east. It's been a while since I flew into Denver but my recollection is the airport is pretty hell and gone from the city.
Stapleton is now "in Denver". I had never been to Denver until a few years ago, and was out for a run with a running club based out of a sports store in a strip mall in Denver proper. I asked what the control tower was for, and someone said they used it for training, which made sense. It wasn't until later on that I realized it was the OLD Stapleton control tower! Right in town! Surrounded by stores and condos and a park.
It is, but in the last 20 years of visiting now and then, it is much more built up on the way "into town" - it used to be that you'd pass that hellhorse and see nothing for 40 minutes but a sign telling you not to stop for prison hitchhikers.
Now there's tons of developments - which is always a problem for these airports. I remember when SEATAC was far outside the city and everyone hated it, now it's crammed in the middle of the Seattle/Tacoma metro area, which is all one big blob city.
