The singer, a novice "river hog" in the pinewoods, chances the "Hulling Machine" rapids rather than portage his canoe. Caught, he prepares to die, gamely shouting "Halloo" to Conner's crew as he passes them. One of them rescues him.
Beck leaves it up in the air whether this was a recitation or a song to which his informant had forgotten a tune. However, it reads more like a recitation, so I've assigned it that keyword. - PJS
This song is item dC42 in Laws's Appendix II. - RBW