Searching for placer gold in river moss can be fun and extremely rewarding for the recreational or small-scale miner. There are many individuals who treat “moss-mining” with the same enthusiasm as bedrock snipers.
While the majority of the gold is fine, the amount of gold recovered by weight, can be astonishing. The overall concept of how fine gold values become entrapped in river moss is fairly simple. When a stream or river is in full flood stage most of the very fine gold values (and some lighter flakes as well) will be moved along in “high suspension” transport. High suspension simply means that the lighter gold values will be carried or “suspended” higher up in the water flow in general, while larger and coarser pieces (including placer nuggets) will tend to be tumbled along or carried lower down in the hydraulic flow.
When a stream or river drops from flood stage, the lightest gold particles will then be left high and dry near or on areas that form “traps” to catch those very same particles. It stands to reason that areas of real moss growing in and along gold-bearing streams and rivers can be excellent gold traps themselves. This is especially true if those mossy areas exist in “strategic” gold deposition points where the abrupt reduction of water flow from flooding or other high water events takes place. Even mossy locations left high and dry above current water flows can be good gold producers.
Moss patches tend to thrive in damp, shady areas along a stream or river course. Moss will trap fine sands, including heavier black sands, dirt, and other small stream material as well as tiny particles of gold. Moss patches or “colonies” left high and dry on the surface of exposed rock, bedrock, fallen trees, etc., should be examined closely along with any underwater or partially covered mossy areas that can be easily accessed.
When sampling “wet” (underwater or partially covered) mossy areas use a gold pan or 5-gallon bucket to catch the contents of the moss as you “wash” the moss by twisting and kneading it. Then pan what you’ve recovered to determine what gold values may exist.
When sampling mossy areas left “high and dry” after stream high-water levels subside, use your gold pan or a 5-gallon bucket to catch the contents of the moss as you twist, knead, and shake it. If you are using a 5-gallon bucket, slap or bang the dried out moss against the sides of the bucket to ensure anything trapped in the moss is forced out.
Clean out any cracks, crevices, or fissures river moss may be growing over or into. These act as natural gold “traps” as well, and may carry good fine gold values as well as larger flakes and coarser pieces.
Save most of the material gathered from your day’s “moss mining” activities and process it using a “Blue Bowl” or spiral wheel concentrator, or even a small-to-medium sized sluice box. Spend your time mining the gold, and process your cons at home.
DO NOT pull out, remove, process, or otherwise destroy all the moss growing within a certain area. If you do, this essentially “kills” that moss colony and makes it hard for any moss to grow back in that location. Leave a few scattered clumps or spots of river moss untouched…that way, you’ll always have river moss’ gold-grabbing potential in that particular location.
The Fraser River in British Columbia is loaded with moss along it’s entire length. I can tell you first hand, I have spent many days mining the moss and have come home with more gold than my digging pursuits, and I might add, without a sore back. I have retrieved many larger flakes as well as small pickers.
One technique we are currently experimenting with, is the use of a 5-gallon shop-vac, powered by a small generator. The shop-vac works extremely well where the moss has been dried in the sun.