River of Lost Souls. Jonathan P. Thompson

editorial targeting the Silverton-area mines and mills, Day had yanked the communities along the Animas River into a statewide row over the dumping of mill tailings into Colorado streams. By that time, Front Range farmers had been battling upstream mines and mills for decades, trying to get state lawmakers to clamp down on mine-related pollution. Mostly it was for naught. But with the irascible Day in the fray, the anti-pollution crowd had gained a potent weapon.

      IF THE RAILROAD WAS THE CATALYST FOR INDUSTRIALIZATION of the region’s landscape, then large-scale milling had an even more profound effect on the mines around Silverton and, consequently, on the water that spills out of the mountains here. When Olaf Nelson and Jonathan Peterson were hit by their first landslide in 1879, San Juan mines were mostly small-scale operations. Nelson and his colleague followed the vein using hand tools and dynamite, then sorted through the ore by hand, picking only the chunks with the highest concentrations of metals, which they took by wagon or burro to the nearest smelter, where the metals would be cooked out of the rock.

      While the miners could scale up their side of the operation by adding more laborers or using more efficient means of transporting ore, they were still limited by the smelting process. Smelting only works on high-grade ores, those containing relatively high concentrations of valuable metals. That meant that the miners had to leave the low-grade ore in the mountain or toss it aside in waste dumps. For the first decade or so, that wasn’t a problem; there was an ample supply of high-grade ore. But there was a lot more low-grade ore to be had, if only it could be smelted. This is where milling—an intermediate step between mining and smelting—comes in.

      Milling ore is simple in concept: You grind up the rocks and separate the valuable stuff out from the “chaff.” But in the late 1800s, engineers still struggled to make it work on a large scale in the San Juans. Mills were constructed at various mines in the Silverton Caldera throughout the 1880s, but none really achieved the desired economies-of-scale until Edward and Lena Stoiber built their revolutionary mill.

      Stoiber and his brother Gustav, German engineers, came to Silverton in the early 1880s to get a foothold in the nascent mining boom. They acquired a group of claims on the shores of Silver Lake, a classic, high alpine gem northeast of Silverton in a hanging basin ringed on three sides by steep, rocky peaks. In 1888, Edward was married to Lena Allen, a young divorceé whom he met in either Silverton or Denver. Soon after, Lena bought into the Silver Lake Mine, becoming an equal partner in the venture with her husband.

      The veins were not especially rich at the Silver Lake, but Stoiber figured he could make a profit there anyway, with proper engineering. In 1890 he had a mill constructed on the shores of the lake, designed specifically to go after low-grade ore, along with a hydropower plant far below on the Animas River to supply the juice to run the thing. While it wasn’t the most efficient operation, it worked well enough to turn a profit from rock that had once been considered worthless, and soon other mines were following the Stoibers’ lead.

      The mills that emerged during this era were enormous, dangerous, noisy structures, usually built up a slope so that gravity could help move the ore through the byzantine process. At the Silver Lake mill, the high-grade ore was sorted out by hand to go directly to the smelter. The rest of the rock went through two crushers before it was further pulverized by fifty stamps, each of which weighed hundreds of pounds, crashing down at high repetitions. The crushed ore was ground down even further by four sets of cylindrical rolls. The resulting fine-grained material was then mixed with water and moved through shaker tables and jigs in order to separate the valuable metals from the rest of the powdered rock. Some mills used mercury-coated plates to capture the gold via amalgamation.

      Put a ton of ore in one side of a mill and, after a bunch of crushing, stamping, screening, shaking, and amalgamation, several pounds of concentrates—a sandy form of high-grade ore that can be smelted—emerge from the other end. That leaves hundreds upon hundreds of pounds of sludge-like leftovers, or industrial waste, known as fines, tailings, or “mill slimes.” The slimes are not benign. Mills in the Silverton Caldera kicked out wastes containing mostly iron pyrite, the main ingredient of acid mine drainage; large quantities of zinc, which wasn’t marketable until about 1916 and is toxic to aquatic life; and other toxic metals, such as copper and lead, that didn’t shake out in the inefficient milling process.

      Nearly all of the slimes—tons each day—along with their acid-generating sulfides and toxic metals, were dumped without second thought into the nearest creek, river, lake, or floodplain. Mills, like slaughterhouses and sawmills and power plants, were built near rivers to utilize the water for power or processing raw materials, and because rivers made handy sewers: Dump your crap in there and watch it wash downstream into oblivion or, in this case, to Durango, Farmington, the Navajo Nation, and southeast Utah’s Mormon country.

      Even if it doesn’t contain otherwise toxic materials, the turbidity from the tailings is harmful. The thick sediment clogs and cuts up fishes’ gills, reducing oxygen uptake, it can coat eggs and hurt their viability, and it blocks sunlight from reaching aquatic plants and algae that are an important part of the aquatic food chain. The silt can clog up farmers’ ditches, town water pumps, and hydropower turbines. And tons of this was dumped into the rivers. It was like the Gold King spill, of a less vivid hue, repeated day after day on nearly every watercourse in the state of Colorado and across the mining country of the West. Naturally, the downstreamers weren’t happy about it, and that ignited a region-wide cold war that would simmer for decades.

      COLORADO MINING GOT ITS START AT THE END OF THE 1850S ON THE FRONT RANGE of the state, in the mountains west of what is now Denver and Colorado Springs, and pollution problems cropped up there first. Clear Creek, a stream that gets its start up on the Continental Divide above what is now the Eisenhower Tunnel on Interstate 70 and then follows the freeway through Georgetown and Idaho Springs, was the initial battleground. The mining-turned-gambling towns of Black Hawk and Central City sit on North Clear Creek, which joins the main stem above Golden. Today, the gargantuan Coors Brewery straddles Clear Creek’s waters in Golden, and the stream joins the South Platte River in an industrial part of north Denver.

      Mines, and then mills, swarmed the upper reaches of Clear Creek, and farms sprouted along the lower sections out in the foothills and plains, drawing water from the stream for irrigation. By the 1880s, Clear Creek no longer lived up to its moniker, and in 1882, the Colorado Transcript ran one of the first articles about an attempt to get the miners to clean up their act, and the water:

      Farmers of Jefferson County are interested in securing legislative action for the purpose of preventing the pollution of the waters of Clear Creek by the mills and mines of adjoining counties . . . the condition of the waters in Clear Creek is becoming more damaging to the farming lands along the creek; that the large amount of sediment carried in the water, coming from the quartz mills along the creek in such quantities and being of a mineral character, whereby it covers and chokes the soil wherever it settles, suffocating vegetation and preventing all growth of any plants, while the pyrites and other minerals contained therein when spread out and exposed to the action of the air, decompose, chemical action occurs in connection with the alkali and salts of the earth, and the copper, arsenic and other deadly and poisonous elements are set free, rendered soluble, and thus with every rain and use of water spreads the destruction over a wider domain of the lands.

      The farmers’ representative, engineer E. L. Berthoud (for whom the Colorado pass and town were named), even offered a partial solution: build a series of settling ponds along North Clear Creek just below the mills. Berthoud acknowledged that this would merely get rid of the particulates, not the acidity and dissolved heavy metals. But it was a start, or it could have been had anyone acted on the suggestion. They did not. Colorado lawmakers made no move to stop the sullying of the state’s waters for years, and the mine managers weren’t about to fix the problem themselves.

      Finally, in 1887, the state gave those battling pollution a foothold, albeit a tiny one: it passed a statute making it unlawful to kill any “food fish” in public waters except for the purpose of eating the fish right away. The new statute didn’t mention tailings or pollution, however, and was premised not on the intrinsic value of water or wildlife or even food, but on the notion that food fish are a type of game, and therefore belong to the state. A decade later