The Rock Island Line was a mighty fine line

Indeed, it may have been "the road to ride," but when hard times hit the railroads, some 40 odd years ago, the CRI&P found itself in real trouble. And unlike the Penn Central, it wasn't too big to fail, finally going belly up in one of the most convoluted bankruptcies in American history.

"The Rock" had two lines in New Mexico, one between Tucumcari and Dalhart, Texas, which still runs today, under the Union Pacific flag, and one that ran between Tucumcari and Glen Rio Texas (and points east), which was abandoned. 

You can get a nice look at the abandoned line on old Route 66 between San Jon and Glen Rio, though it's a bumpy ride. Pictured is the only remaining trestle on this portion of the old right of way.