"Sweetgrass Hills" on the Canadian border
“Horizon” is a term of terrain, which has been pulled by metaphor into other human experience. It is the limit of what we can “see” and that doesn’t mean just by looking, but also by comprehending. The limit is set by experience and the acceptance that there is an edge, and beyond that edge sometimes assuming there is at least nothing of much importance.
From here I see the 49th parallel marked by the Sweetgrass Hills, the Continental Divide marked by the Rockies and a swell of land about a mile to the east, probably pushed up by the glaciers that once covered this land, although the Sweetgrass Hills stand as a refugia where some animals and plants were able to persist in a sea of ice. A glacier is something that moves, a horizon that approaches and recedes, basically a frozen ocean.
To many people here, even Native Americans, “history’s horizon” is the arrival of white people because they brought written history, the “real” history, so nothing happened until maybe Columbus or Lewis and Clark or the Conrad brothers. Montana had to pass a law to require schools to teach Native American history. Or maybe the beginning was Montana becoming a territory, which happened in receding stages, smaller and smaller areas, until it solidified into a state. Parallel with that, the reservations were created (closer to the coalition of Italy and Germany into nations back in Europe than I would ever have guessed) and then their horizons closed in. Writing meant boundaries on maps, not the ridges and rivers of reality. "Belgium" was created in 1830.
Probably the glaciers didn’t arrive so quickly that they could be seen moving, as in “Game of Thrones.” (“Winter is coming.”) But they must have pushed the humans and animals south, slowly enough for even the plants to move along, growing a little farther south every year the way they are moving north now. When the ice left, melting back, it created great torrents of water that hydraulically carved the land, but in the gentler times there would have been at least a summer greenbelt along the edge as the plants, animals and people moved back toward the north.
In the past it has been assumed that Native Americans got to this continent by walking across the Bering Straits, imagined as a sort of bridge like the gangplank to Noah’s ark. But now the geologists — and history is becoming geological so that horizon can be about land again — say that Beringia was more like Bangladesh, just above sea level, a broad and marshy land where mammoths roamed, enticing the humans with their spears and dogs.
Some evidence of human occupation of the Americas precedes the withdrawing of the glacier that blocked Beringia and probably sank it with rising sea level (a kind of horizon) when it melted. Along the coast of South America, the evidence suggests, people came by boat on the ocean current gyres from South Asia. Even jungle debris rafts from SE Asian cyclones wash up with creatures riding them.
But wait! There’s more.
“Written history,” meaning decipherable traces of the past, can be found in the structure and vocabulary of linguistics, the gene and epigene records in cells, the isotopes and structure of molecules, the lines and shapes immortalized in stone, and so on, each providing their own horizons of events in the deep primordial past before there were humans — before there was life of any kind. We've become fairly used to thinking about Pangea.
No one has thought much about what people were on the North American continent before the last glacier. There has been little consciousness about people who did not move out of a territory because of a wall of ice but because of drought, abiding dryness that couldn’t form ice. Slowly new suggestive evidence arises and converges, not so much a horizon as a valley.
“. . . all Native Americans stemmed from a single group that later diversified into two branches: one that included Amerindians, who occupied North America south of the ice sheets and also Central and South America, and one that included Athapaskans, Paleo-Eskimos, and Inuit in the far north.” To my eye the people around Lake Baikal look like Blackfeet, said to be Athapaskan. In the past some have gotten interested in a globe with the Arctic, an ocean, as the center instead of the equator. At some points the Arctic has been open water.
A little girl’s “pinky finger” has revealed far more. Though 40,000 years old, she left enough DNA to reveal a whole new branch of our species, one named “Denisovian.” Not like Neanderthal. Like Australians. Like the SE Asian people who would have set out on boats for horizons along the coast of South American. But wait — there’s more.
(First I want to interject an irrelevancy which is that in Blackfeet country a special tie between little girls and their fathers existed by custom. If the father were grieving, it was sometimes the practice to displace his pain onto the daughter by cutting off a joint of her finger. After all, a man must be able to fight and hunt and if he loved the child, it was still a sacrifice. There’s a poetic connection with the Denisovian fossil — isn’t there?)
The “more” is that investigation of far north Eurasian populations revealed Denisovian genes like those of today’s Native Americans. There is talk of “ghost populations,” paleopeoples who no longer exist but can be implied from evidence. In terms of the big glacier event, these people at the limits of early habitation seem to have been more in eastern and northern Eurasia, in a great area of desertification rather than glaciation that could have driven them onto the barely connected American continent, both east and west, only to confront glaciers. They had gone “over the top” as we imagine the world.
“The Last Glacial Maximum (LGM) was the last period in the Earth's climate history during the last glacial period when ice sheets were at their greatest extension. Growth of the ice sheets reached their maximum positions in about 24,500 BCE. Deglaciation commenced in the Northern Hemisphere gradually between approximately 18,000 to 17,000 BCE and in Antarctica approximately 12,500 BCE, which is consistent with evidence that it was the primary source for an abrupt rise in the sea level in about 12,500 BCE.” (Wikipedia)
“According to one theory, Neanderthals, Denisovans, and modern humans are all descended from the ancient human Homo heidelbergensis. Between 300,000 to 400,000 years ago, an ancestral group of H. heidelbergensis left Africa and then split shortly after. One branch ventured northwestward into West Asia and Europe and became the Neanderthals. The other branch moved east, becoming Denisovans. By 130,000 years ago, H. heidelbergensis in Africa had become Homo sapiens—our ancestors—who did not begin their own exodus from Africa until about 60,000 years ago.” https://genographic.nationalgeographic.com/denisovan/
Horizons, even time-horizons, when they are crossed, make us realize the possibility that there are worlds on the other side and we get curious about what they are like. We have mostly thought about re-population in terms of animals, who are now repopulating the cities (coyotes, raccoons and hawks) and will one day repopulate the great ecosystems where we raise grain as long as there is precipitation. It’s not likely to be glaciers bearing down on us, but rather drought.
The grizzlies are pushing, leaving the high horizon of the Rockies and coming into the river valleys, because water is life. But indignant humans want pushback. It’s water all living things emerged from, compete for, and must keep contact with. It is one of the crucial edges of biological homeostasis. We cannot live in dust storms, but we might need to try. Think “Dune.” Think about ghost populations.