Amtrak Explorer is an interactive map of America's public railway network created by Rachel Binx, a creative technologist specializing in data visualization, mapping, and other things. You can click on your favorite lines and cities and see when the trains come and where they go. And then there's Amtrak's own visualization, not so pretty but showing where the trains are right now.
South Dakota and Wyoming are the only states without Amtrak services. Apparently the tracks in S.D. are just too run down to be used for passenger service and upgrading them would not be worthwhile for the small volume of passengers served. From the news archives it seems Wyoming has had on-off service since the 80s–mostly off–but locals wouldn't mind having it back again. I've ridden the Coast Starlight and the Pennsylvanian a number of times, and it was always lovely.
I like how the design of the map is reminiscent of the NORAD big screens in Wargames. Just the perfect aesthetic for clicking on things in America.
Below, a map showing all the tracks—including freight.