I was talking the other day about how under-represented organic technology is in archaeology generally, and especially on the Northwest Coast, where the old adage is that 95% of the technology was made out of plants (trees, wood, bark, roots, grasses, seaweeds). A classic example of this phenomenon are anchor stones and sinker stones. While some of these stones had grooves or perforated holes (and are thereby very visible and durable in the archaeological record), many may have been made by the more simple, subtle and expedient method of simply wrapping line or basketry around an unmodified rock. When the organic component rots away, as it will most of the time, then the archaeologist has, well, an unmodified rock.
Anyway, it was a lucky stroke for my current interest that I came across the above photo from the University of Washington Digital Archives.