What do 30 million American bison, the completion of the transcontinental railroad, and the discovery of superphosphate fertilizer have in common? A lot, as it turns out. In 1868 they became critical elements in the formation of an entire industry, one that thrived for over 20 years. It helped finance the settlement of the Great Plains, ensured solvency of numerous new railroad lines servicing the settlers, and provided vital fertilizer for crops across the entire continent.

The confluence starts with phosphorus. Without knowing why, early humans figured out that their plants thrived when they added ground up bone to their seed mix. In 1840, the answer became clear. Phosphate, the P in the NPK that is listed on every bag of fertilizer at the garden center, is crucial for robust flowering, fruiting, and root growth. Bone is an excellent source of phosphate because the chemical notation for the calcium crystal that makes bone strong and hard is Ca₅(PO₄)₃(OH). There are three phosphorus atoms in every molecule. In this form, however, the phosphate is not very soluble, and it takes a long time for a plant to incorporate it.

In 1842 an enterprising chemist mixed bone meal with sulfuric acid, which changed the phosphate into a form that was readily available to plants—superphosphate. Plants loved it. Farmers couldn’t get enough of it.

During the same years, settlers were rambling west across the Great Plains with trains rumbling not far behind them. The Native Americans and roaming buffalo both proved vexatious to the western migration, and it became government policy to exterminate the bison as a means of subduing the Indians. Furthermore, the bison herds were collision hazards for locomotives, which could not stop quickly. To escape blizzard winds, the bison particularly liked to stand on the tracks where the line cut through the hills. Trains could be halted for days. For these reasons, it became common practice for hired marksmen to shoot the bison from moving trains. Their hides might be harvested. The remains were left to rot. Over roughly 30 years, tens of millions of bison were reduced to a few thousand.

Bison skeletons covered the prairie. Where ever a railroad line passed nearby, it became feasible, actually lucrative, to pick these bones up, put them on a train headed back to St. Louis, Detroit, or Chicago, and sell them to a fertilizer plant. Baked and ground, bone also filtered sugar during the refining process.

The homesteaders benefited, particularly in their first year on the prairie, when they did not have crops to trade for needed farm equipment and food staples. The railroads benefited, because the trains brought goods west and would otherwise return empty were it not for the bones.

An industry blossomed. A homesteading family or team of half-breed bone pickers could harvest a ton a day, cart the bones into town, and sell them at the local railhead for $5 to $8. This was at a time when a family could manage fine on $10 a week. Bone brokers sprung up in every town along the railroad line. They bought bones from the pickers, stacked them in huge piles and windrows, and sent them east on the next passing train. The Native Americans, however, did not participate in this industry out of respect for the bison, which for millennia had provided them food, shelter, and clothing.

As new railroad lines spread west, new opportunities for picking up and delivering bones within practical distances also expanded. Sometimes the bone pickers would advance miles ahead of a new railroad line extension and wait with their stash until the line arrived. What started in an east-west band across Kansas and Nebraska eventually extended south into Texas and north deep into the recesses of Alberta and Saskatchewan, where local boosters eventually arranged to have the name of their town, Pile o’Bones, changed to Regina.

When pickings became slim, bone pickers would throw in antlers, which are also bone, and, according to some accounts, bones raided from Indian graves. The brokers and factory owners didn’t seem to mind. The half-breed teams would also burn the prairie to ease the burden of finding the bones in the grass. They cannily started the fires close to the railroad tracks so that they could plausibly attribute the flames to sparks from locomotives.

Accounts of the numbers and tonnage of the bones collected are mind boggling.  Although nobody kept an overall tally, several observations are revealing.

Brokers in Minot, North Dakota, moved 375 tons of bone in each 1887 and 1888. This grew to 2200 tons in 1890. By mid-June of the same year, pickers had brought the remains of over 100,000 animals into Saskatoon alone. By August, a shortage of railroad cars resulted in 165,000 skeletons stacked in one pile waiting transport. Other smaller piles were nearby.

Overall, bone picking was roughly a $40 million industry involving two million tons of bones—enough to fill two rows of box cars crossing the continent from San Francisco to New York. By comparison, the previous “big” bone industries–buttons and jewelry boxes–were eclipsed many times over. Yet none were sustainable. By the early 1890s, railroads had expanded into all of the areas previously occupied by the bison, the prairie had been picked clean, and the industry collapsed. Fertilizer manufacturers turned to a mineral form of phosphorus to continue making fertilizer.

Bone meal fertilizer is now derived from the meat packing industry, you can buy it at the garden shop. It provides slow-release phosphorus nutrition for your plants. Let a steer eat your flowers, butcher the bovine, grind its bones, fertilize your plants again. The phosphorus goes round and round, but bison are forever out of the loop.

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