Sentence:  High <WSD>Park</WSD> is a depression of 10 or 12 square miles in extent ... at a general elevation of 7,500 feet. Its smooth floor is partly due to volcanic tuff of the western volcanic area, but chielfly to a find lake-bed deposit of yellowish sandstone.... 
Meaning of the word marked with <WSD> tags:  A wide, flat-bottomed valley in a mountainous region.