Who invented mountain biking?

I don't think a single person invented mountain biking. Bikes have been ridden off-road since their invention. I know that the modern sport started in the 1970's. Okay, well downhill biking was "hucking" by canadians,

Joe Breeze built the first modern mountain bike frames, but without the ideas and innovations of a whole bunch of other people, he'd have had nothing to hang on them, and no inspiration to build them in the first place.