The photos in the first post above are of Duane Danielson's two-rail O scale railroad, modeling the NP and GN and located in Durango Colorado. Sorry to revive an old post, but I feel it's necessary to inform folks here that this railroad has sadly been dismantled recently (I'm also sorry to report I helped).
These photos above are pretty surprising to see, as they were taken very early on before Duane had made any scenery that can be seen in the youtube video linked (https://www.youtube.com/watch?v=2-nOkCzLeyg). What's even weirder is that I recognize a lot of the benchwork photographed that I helped rip apart... Anyway for more details view this NGDF post about Duane Danielson's O Scale railroad and its demolition: http://ngdiscussion.net/phorum/read.php?1,402724