What opened land to ranchers in west texas and the panhandle to in the late 1800s

They are directly and forcefully affected every day by their natural environment. Typically, the first thing they do when they step outside early in the morning is to look for sign of a rain cloud. Rainfall or the lack of it, the weather cold or hot, the availability of water are concerns with which they must deal day by day, year by year. 
hope this helps 

The answer is ozone layer.