This is what we know about water-pump windmills, thanks to a visit to the American Wind Power Center, in Lubbock, Texas. Located in a long riverside park that snakes through the city, the Center displays about fifty working windmills on its grounds, making a beautiful sight, and inside 
Outside the museum ...
the building are another hundred models. Once there were dozens of windmill manufacturers, but now there are just two -- the Aermotor company of San Angelo, Texas, and another in Nebraska. That's not counting the Australians, who make a giant windmill under the brand name of Southern Cross. The museum is just one of the stops along the Wind Power Trail, which winds in a lazy circle through Texas, Oklahoma, Kansas and Nebraska.
The museum is staffed by volunteers, and one, an older lady who had spent all her life on cattle ranches, immediately grabbed hold of us and eagerly described the acquisition of the collection, spearheaded by another woman, a professor at Texas Tech, who saw the collection for sale and 
... and inside
wanted to acquire it for the University. She succeeded, and the museum was born.
As windmill idiots, we had to learn about all the engineering problems: using a counter balance so that the windmill doesn't fall over when the wind is blowing; and providing a method of feathering the blades when the wind is blowing too hard. We already knew about the easy technique of using a vane to point the blades into the wind. Sometimes a second vane was used which caused the windmill to turn away from the wind when it was blowing too fast. We were unfamiliar with the design which split the blades into folding sections; when the wind blew hard, the mill changed shape to look like a bottomless wooden basket, and the air moved right through the hole without damaging the sides.
Windmill weights
Even when better designs preserved the windmills from storms, the ranchers still had plenty to do to maintain the mills, keeping the bearings oiled and greased and inspecting the framework and blades for damage. If a blade was broken the mill would be out of balance, and the bearings wore out faster. The industry worked to develop sealed bearings which would last longer under the harsh plains weather.
It was surprising that the inventors did not flock to Washington to patent their designs, but the business went along with lots of good individual ideas, and windmill salesmen travelled from one ranch to another carrying a working model of their mill. The first actual windmill patent in the U.S. was in 1854. In the early days lots of self-sufficient ranchers built and repaired their own windmills.
A full-grown steer drinks 15 gallons of water at a time, so windmills were absolutely essential if the dry plains were to be used for ranching. The number of mills required related to the size of the herd, but of course that was also limited by the quality and extent of the pasture land. Just as the fierce winters required the rancher to shelter the cattle, so the long hot summers made plenty of good windmills an 
Working models
absolute necessity.
One of the real impetuses for windmill development in the plains was not cattle ranching at all, but rather the railroads. Watering stations were spaced twenty miles apart to allow steam locomotives to take on water, and before electric power these watering stations were all powered by windmills.
Even with modern technology, windmills are still a vital part of western cattle ranching; they're much more cost effective than laying power lines to put in electric pumps. With the cost of generated energy continuing to rise, while the cost of the wind stays at zero, windmills will be around indefinitely.