1996 Ford Ranger Clutch pedal won't depress

well its hydraulic and it should not be rock hard unless the line is blocked or something. anychance it could be frozen? brake fluid absorbs water and holds it in suspension. the fluid in the clutch master resovoir is brake fluid. I run into it in Alaska all the time. not usually on clutches tho. they just don't get hot enough to suck in enough water to freeze it up. could also be a broken slave/throwout brg that is seized on the output shaft of the tranny. good luck and do a little more diagnostics.