Quite influential on me

I've only seen this once. I was a kid & it was on tv one time in the 70's. I was driving to work this morning & for some odd reason, the scene where Jan Michael Vincent is holding up the buckets of sand entered my head. So i had to look this up. Man, i didnt even know the title of the film! I just adore "alternative" movies of this era. Such a special time. Cant believe Jan Michael Vincent was not a bigger star.