The Master Oak
The activity of the mind of George Will was matched by the activity of his legs. Son and heir of the seedsman Oscar Will of Bismarck, he put his Harvard education to work on everything around him, from horticulture to folksong to archaeology. And he was a boots-on-the-ground sort of guy.
Throughout the first half of the twentieth century, Will was trying to figure out the dating and succession of earthlodge village sites in the Missouri River valley. So he went looking for old trees--specifically, really old bur oak trees. He thought perhaps dendrochronology, tree ring analysis, would provide evidence for the dating of archaeological materials.
The preferred timber for the structural support of old earthlodges was bur oak. The State Historical Society of North Dakota possessed many specimens of bur oak materials from the earthlodge sites Will was interested in.
So his scheme was to match the tree-ring patterns in these specimens with those of known, living trees, thus dating the fragments. After that he would match old log samples against even older log samples, extending the chronology back even farther. All this is detailed in his report, Tree Ring Studies in North Dakota, published as North Dakota Agricultural Experiment Station Bulletin 338 in 1946.
Will located his master oak, the touchstone for all his work, in the SW corner of S13 T138N R81W, on the farm of a man named Frank Wilcox, some six miles northwest of Bismarck. He felled the master oak to acquire a slab with 373 growth rings for analysis; worked through some analytic problems too complicated to explain here; and then extended the work back in time according to his plan. “Thus there is available,” writes Will, “a continuous record of precipitation over a period of five hundred and thirty-six years.”
Will’s core purpose was the dating of archaeological sites. So how did his work become an agricultural experiment station bulletin? This was because agriculturalists, emerging the great drought of the 1930s, were concerned and perplexed as to the nature of climate on the Great Plains.
Thus Part II of Will’s tree-ring bulletin is headed, “Tree Rings and Precipitation Records.” His detailed dissection of the dendrochronological record determines that wet years and dry years come in bunches--periods of years or even decades that could be classified either wet or dry--but there was no discernible cyclical pattern. They could not be predicted.
The frustrating part of this is, Will never asks the questions I am interested in. He is preoccupied with cycles. He never so much as considers the possibility that there might be underlying systemic patterns in the longue durée, as historians like to say, meaning, in the long term, over centuries. I’m talking about climate change. I’m not talking about what causes climate change, you can argue that among yourselves. I’m concerned with climate change as a force in history.
It seems to me, for a number of reasons, that the Little Ice Age is important to the emergence of equestrian indigenous cultures on the northern plains, which happened, my friend Dakota Goodhouse has determined, in the 1680s. I suspect Little Ice Age winters here were really cold but also open, making it possible to keep horses. Further, I think the closing of the Little Ice Age in mid-nineteenth century, the warming of the prairies, facilitated the onrush of Euro-American settlement.
In the very logs examined by Will there resides unused data differentiating winter and summer precipitation. Someone needs to go back to this and tell us what deep winter was like in deep time.