There is a lot of history in this photo. The Falls of St. Anthony were the only major waterfall on the upper Mississippi, originating in the time of the glacial Lake Warren and steadily cutting upstream in the thousands of years since then.

The falls was also the head of navigation -- the highest point reachable by boats moving upstream -- so not only could timber be brought down from the North and grain be brought in from the immense agricultural areas of the upper Midwest and the waterpower be used for processing, but also shipping was possible down the river by steamboat.

Locks bypassing the falls were not built until decades after this photo.

Lots of the structures in the area remain, just hidden by trees now.
https://goo.gl/maps/5ZcgudRwQFyTL8Jo7

Pillsbury's "A" Mill, now lofts:
https://goo.gl/maps/qfUFt36UseW2f11W6

But all else is pretty much gone.

Many of the buildings seen in this photo are still standing - notably the Pillsbury "A" Mill, now converted into residential lofts. Crown Iron Works -- "the world leader in oilseed extraction" -- is still in business, with locations around the world; the building in this picture is long gone; Crown's Twin Cities location is now in the suburb of Roseville. My Uncle Ray of sainted memory (d. 1955) worked at Crown. Of course the Pillsbury brand is still going strong, although archrival General Mills acquired Pillsbury in 2001, and then sold its baking products division to International Multifoods, who in turn sold it to Smucker's. But the Pillsbury brand name lives on, thanks no doubt to the popularity of the Doughboy.

I would challenge the 3 negative panorama claim. This looks like a Kodak Cirkut camera image.

[I personally stitched this image together yesterday from the LOC's three glass negatives, which can be viewed here. Using Photoshop, it took a little over an hour. - Dave]

The St. Anthony Falls historic milling district, using the power of falling water at St. Anthony Falls, first gained prominence with the construction of large-scale lumber milling from logs floated down the Mississippi from central and northern Minnesota pine forests. Flour milling boomed later and numerous mills along this stretch of river changed the way food was produced, marketed, and distributed and changed the way we think about food.

https://www.nps.gov/miss/planyourvisit/uppestan.htm