USA trip

Hi
In September this year me and three of my freinds are going to visit USA for two weeks.
We are all danish RR fans. Beside our love for danish railroad, we are all interested in US railroad, especially narrow gauge.
The main purpose of the vacation is to see as much railroad as possible. But we wants to se other attractions as well.
We have allready planned to see a lot of interesting things:
Golden RR Museum, Forney Museum, Caboose Hobbies, Pueblo RR museum, Royal Gorge, Mears Jct, Gunnison, Black Canyon, Durango & Silverton, Cumbres & Toltec, The Meteor Crater, Grand Canyon, Kingman, Las Vegas and then back east to see the remains of RGS, Mesa Verde, Leadville, Tennesee Pass, Como, Georgetown Loop, Idaho Springs, Central City, Moffat Tunnel and ending up with a second visit to Caboose Hobbies and then back home to Denmark again.
Though we have planned the trip for a long time, and a pair of us have visited the states before, we migth have missed some interesting railroad places along our route.
Does any of you guys have any suggestion ?
Erik Priess