Old Stream Layers at Crow Creek - 7/10/99

Sluice headed up cable

I finally got my dredge completely out of Crow Creek canyon this weekend. Water conditions in the canyon forced me to don my drysuit; I did not feel comfortable trying to cross the creek in waders while carrying a six foot long sluice box over my head. I was tempted to leave the last items until the water dropped in the fall, but I already had a buyer for the dredge, and so had to get it out. After carefully fording the sluice, suction hose, and other gear up the canyon to the base of the cable pullout, I stripped out of my drysuit. Then came numerous trips in and out of the canyon, attaching gear to the pulley system, then climbing up and pulling it out. By the time I finally got it all out to the parking lot, I was ready for a break.

The pictures below explain why I dredge Crow Creek in the early spring and late fall. It has been a dry summer, but since Crow Creek is fed by a small glacier and snowfields, it remains at flood stage all summer. The water is fast enough to be barely crossable, and is gray with glacial silt. Compared with the slow moving, clear water of spring and fall, it is simply not worth fighting the season. In particular, the inability to see the material means more worthless material is dredged, and more frustrating hose clogs occur. Still, there are those who work the creek in the summer and do well; they simply have more patience than I have.

    
Crow Creek on July 10, and back on April 24

I decided I had to find at least a little gold before I went home, so I grabbed my trusty metal detector and headed up the creek. Mine owner Sean Toohey was working with a backhoe up the creek grooming a place for a GPAA mining party the next weekend. He was also scouting for a place to mine in the future.

Old streambed layers

A rather obvious (to my eye, at least) layer of cobbles was cutting across a bank exposed by floods a couple of years ago. A looser cobble layer rests on a finer grained, and much tougher lower layer. The fine-grained lower layer is much older, and formed a false bedrock surface for the more recent upper streambed layer. At one time Crow Creek itself was running up at this higher point, and the cobble layer represents the bottom of this now high and dry deposit. Remnants of older streambed material, perched above and parallel to the existing steam are referred to as "benches" or "high bench deposits". Often a flattened area on the banks above the current creek can indicate a bench deposit, but often times material sliding downhill from above bury the deposits so that they are not immediately obvious. Such is the case at this location.

I checked the exposure with my detector, and was not too surprised when I had found three small nuggets in less than ten minutes. They all were at the base of the cobble layer, on top of the fine-grained layer. They were also of a chunkier character than the gold found in the canyon downstream, having been subject to less stream action since being released from the gold veins upstream.

Small nuggets from the old stream layer

The two larger pieces are 4 grains each, while the smaller piece is a 1 grain nugget, for a total of 9 grains. Not much, but not bad for ten minutes. Sean promptly declared the location "Steve's Bench" and made plans to expose the hillside with the backhoe in the future. Chances are the deposit is limited in extent, but one never knows until a little digging is done. In any case, the area bears more attention from metal detector users and others.

~ Steve Herschbach
Copyright 2000 Herschbach Enterprises