Grasshopper - looking for ID

A noisy, usually very dark-colored slender grasshopper of mountains; with tegmina long and wide; the hind wings wide and usually appearing half yellow - half black. In some individuals the coloring may be lighter and/or the tip of the hind wings may be nearly clear, but these can usually be identified easily by habitat and association with darker individuals. Hind tibiae vary in color, but are most often brownish, nearly black, or blue (but may vary to yellowish, greenish, or mixes of these colors).