The Sons of the Forest zipline gun is a very important key item that's easy to miss, so here's the location of where it is hiding.
Sons of the Forest Rope Gun Location Guide - KeenGamer
Sons of the Forest: How to Get and Use Zipline
Sons of the Forest: How to Find the Zipline Rope Gun - IGN
How to Use Zipline in Sons of The Forest
How to get rope in Sons of the Forest and zipline Rope Gun location
Rope Gun - Sons of the Forest Wiki