There are two types of "tailings" on War Eagle Mountain. The first is ore that was pulled out of the mines and processed "visually"- anything that didn't have visual gold in it was left behind, since it wasn't worth transporting by mule either down the mountain or to one of the mills set up on the mountain. This "visual" cutoff is probably responsible for the 2 oz/ton cutoff grade mentioned so often. Anything less probably didn't have visual gold. This ore that was left behind will probably be less than 2 oz/ton, but will still be high grade- it was pulled out of the mountain along with the > 2 oz stuff and was probably within a few feet of the veins, if not part of them.

The other variety of tailings will be those that were processed with the available equipment of the day- mostly stamp mills, and maybe cyanide leaching or mercury amalgamation. In the only reference to the efficiency of stamp mills I've been able to find so far, only about 40% of the gold (and silver too?) was removed by mechanical "concentration", with most of the the gold being removed by mercury amalgamation (50%) or cyanidation (5%) (Metallurgical and Chemical Engineering, Dec 1914, Company reports, pp 744-745, link). Even with these methods, about 6% of the gold was left behind. I assume the stamp mill leftovers SFMI is starting to mill were not subject to amalgamation, so they may have still have over half of the gold left in them! Even if only 6% of the gold is left behind, with average grades of 2.5 oz, that's still .15 oz/ton, or 4.5 g/t. 4.5 g/t is still excellent for already mined material that only requires hauling and processing. If only mechanical processing was done, then we may see tailings that still have well over 1 oz/ton.

SFMI has said that they will process the lower grade material first as they work out the bugs and fine tune and ramp up the mill process ("lower" grade does not necessarily mean "low" grade). I assume this is some of the material that has already been milled. My guess is that we may see initial results that reflect anything from 5g to 1 oz/ton. I'll set my expectations around 5 g/t (reported assays are around 6 g/t), but I won't be surprised to see something much higher.

For pictures of the tailings piles and shafts and what's left of the various mine and mill structures on and around War Eagle Mountain, check out this link to a report from the Idaho Geological Survey: Abandoned and Inactive Mines in Southern Idaho.