I finally figured out how to spot a midden in dense forest cover after five failed attempts.
I started using a simple metal rake to gently scrape the top layer of pine needles in a specific grid pattern near the old logging road in the Oregon woods, and it revealed a clear concentration of charcoal and shell fragments that we almost walked right past.
A metal rake in the Oregon woods is a smart move. I would have never thought to grid out pine needles like that. Finding charcoal and shells after five tries must have felt pretty good.