In the case of Olaf's pic, in 1967, the Antonito Tank was out of service. Westbounds took water at La Jara and Lava.
In days of heavy westbounds, trains would have had to get water at Antonito, then at Lava. A heavy 70 car train would have the engines working as hard as they would up the west side of Cumbres. They would drink a half a tank of water getting to Lava.
From Lava, they would get water at Sublette. If the train was heavy, they would tank up at Osier, instead of Los Pinos. (As a side note: Has anyone got a pic of a Rio Grande freight getting water at Los PInos? I never have.) The engines would get water at Cumbres before heading down the hill.
One way of looking at this the locomotives carried enough water to work at capacity for 1-1/2 hours or about 20 miles before draining the tender down to the point where the injectors won't work well.