Three photographs of  coaling tower & sand house in Chama, New Mexico as photographed in June of 2009.  

The first shows both, the sand bin is to the side away from the coaling tower.  Tracks run on both sides of the structures, but this is the side used for servicing  locos.

In the one below, note the desert raven on top of the tower, they nest on the tower every year, and a properly weathered coaling tower would have streaks of raven poop down the side.  This is the side used to fill the tower, locos are serviced on the opposite side

 The sand house, this is the side used for servicing the locomotives, note the sand bin beside the building, the beams on the other side connect to the coaling tower.