"Were there other commonly used forms of travel by river?"

Yes, there were: [Burlaks][1], [(timber) rafting][2], and [rowing][3]. 


  [1]: http://en.wikipedia.org/wiki/Burlak
  [2]: http://en.wikipedia.org/wiki/Timber_rafting
  [3]: http://en.wikipedia.org/wiki/Watercraft_rowing