Ran the downtown loop with STA while FWA was at his first in-person lesson at MacPhail since March of 2020. Downtown loop = stone arch bridge + st anthony main + nicollet island + boom island + plymouth bridge + west river parkway. A great afternoon for running, not too hot. We checked out the new park and the indigenous restaurant opening next month. Nice!
All morning, I was putting together a rough timeline of the history of the area, starting 12000 years ago when the glacial Lake Agassiz spilled over its edge and traveled through the River Warren all the way to St. Paul. For some time, I have been confused about conflicting dates I encountered–was the gorge formed 12000 or 10000 years ago. Today I learned more: 12000 years ago the River Warren eroded the softer sandstone under the limestone near downtown St. Paul which created the massive—apparently bigger than Niagra Falls–Warren Falls. For almost 2000 years the falls slowly traveled up the Mississippi River to the confluence (where the Minnesota and Mississippi Rivers converge, near Ft. Snelling). Then it split into 2 waterfalls, one followed the Minnesota River then fizzled after entering an existing river bed, the other followed the Mississippi River and slowly carved out the gorge, traveling 4 feet every year until things become more precarious and erosion accelerated–about 100 feet a year in the 1860s, right before the falls had to be shored up with a concrete apron in 1870. So, I guess you could say the gorge began forming 12000 years ago when the Warren Falls started it’s slow march from St. Paul, or you could say 10000 years ago when the falls reached Ft. Snelling and moved upstream to Minneapolis.
We ran by some of the entries in my timeline, like the Hennepin Avenue bridge–the first bridge to span the river, built by Franklin Steele in 1855 and replaced 3 times, or the Stone Arch Bridge, built by James J. Hill in 1885, or St. Anthony Main which is older than Minneapolis but became a part of it in 1872.