In addition to Professor Dan Hernandez’s fences, the stakes that indicate Professor Mark McKone’s plant community studies and the bird count posts there is another set of very interesting, but often overlooked markers hiding in the Arb. In at least two spots, it is possible (though not always easy) to find markers that correspond to early land surveys of Rice County carried out around 1850! These markers are part of historic surveys which “serve as fundamental legal records for real estate, as an essential resource for surveyors, and as an analytical tool for the state’s physical geography prior to European settlement” (http://www.mngeo.state.mn.us/glo/). What makes these records salient to Arb management is that these surveys include valuable information about the landscape and the flora in the Arb before European settlement. This information helps Arb Staff make educated decisions about which areas of the Arb were historically oak savanna or prairie. Entries such as:
“Set a post for the center to the ¼ section [½ mile].
burr oak 10” in diameter, [southwest] 74 links [~14.9 meters]
burr oak 12” in diameter, [southeast] 75 links [~15.1 meters]”
would suggest that, based on the distance between the trees and the pole, that this area was oak savanna. An entry from a point farther south, has much greater distances of 74 meters and 68 meters between burr oaks, indicating that this area was a transition zone between the treeless prairie and the slightly more wooded oak savanna. In addition to marking the nearest trees, surveyors also commented on the soil conditions and type of land. A common description of the terrain in the lower Arb is “landing rolling, here 2nd rate.” Soil could be ranked as first-rate, second-rate, or third-rate depending on how productive for farming it appeared. These notations were important to potential settlers who were being encouraged to expand westward, and needed information about where to locate their future farms. In addition to noting the surrounding scenery, the surveyor’s main objective was to mark the boundaries of townships. Public Land Survey townships (not political) were six square miles, comprised of 36 one mile square sections. These distances were measured out using links and chains. One chain equaled 66 ft, therefore, one mile equalled 80 chains. In the lower Arb, along the medium loop trail (near where it turns), there is actually a metal disk marking one of the survey monuments.
So, next time you’re walking through the Arb - although you may not be carrying a 40+ pound metal chain - it is definitely worth contemplating what the Arb might have looked like to these early adventurers. And thanks to their notes, we actually can make reliable estimates about where the boundaries of each ecosystem would have been.
- Jasmine Cutter '13, for the Cole Student Naturalists