This is video of what I think is the Los Angeles Junior College mud battle of 1936!

https://www.youtube.com/watch?v=J85uKvaU7Rs

And a little more...

http://www.gettyimages.co.jp/detail/%E5%8B%95%E7%94%BB/montage-college-men-mud-wrestle-montage-men-engage-in-tug-of-%E3%83%8B%E3%83%A5%E3%83%BC%E3%82%B9%E5%8B%95%E7%94%BB/502230816

Plus a couple of pics from the same event:

LA didn't have all the fun. Here's two more, from Villanova 1936 and San Francisco 1938.

A few more pics from LA, 1936. And one more, which looks more like 1950s to me (the last one)