Is Lake Pepin a lake?


When we first moved to Minnesota many years ago, we were naturally aware that there are a lot of lakes here — 10,000 of them, rumor has it. We also came to understand that many of those “lakes” are actually ponds.

Still, we we’re shocked — shocked — to read today in the Rochester Post Bulletin that one of our favorite spots in all of Minnesota (which we visited this weekend) is not a lake at all:

Lake Pepin really isn’t a lake, not in the Minnesota sense. Instead, it’s a reservoir of the Mississippi River formed when sand pouring down the Chippewa River from the heart of Wisconsin blocked the river at what is now Reads Landing. It’s the widest spot on the Mississippi River, except when it floods. Pepin was once much longer, stretching up to what is now the Twin Cities. But over the millenia, it has been slowly filling in. Such lakes are very rare worldwide.

“Not in the Minnesota sense?” What does that mean? Lake Pepin isn’t good enough for you and your 10,000 close friends, Minnesota?

Check ye olde Encyclopedia Britannica:

It may be said, however, that rivers and streams are relatively fast moving; marshes and swamps contain relatively large quantities of grasses, trees, or shrubs; and ponds are relatively small in comparison with lakes. Geologically defined, lakes are temporary bodies of water.

Not being from Minnesota, I’m unqualified — as is Encyclopedia Britannica — to bring a Minnesota sensibility to this question. Over to you, native Minnesotans.

  • I’m not officially from Minnesota – I moved here as a pipsqueek in 1983 with my family (by pipsqueek – I was almost 2). Do I think Lake Pepin is a Lake? No. Reservoir? Perhaps. Really wide part of the Mississippi River? Definitely.

    Especially considering it’s only a % (magnitude?) larger than the river itself before the “lake” starts.

    If the Mississippi were to be 1 mile wide where it enters Lake Bemidji, and Lake Bemidji were 2.5 miles wide, would that be a lake? I would venture you would say no.

    But I don’t know what I’d call it other than what I said earlier: “[a r]eally wide part of the Mississippi River.”

  • John P.

    As a native, I am as puzzled as Bob.

    There are plenty of reservoirs that are called lakes. Pepin always seemed like a wide spot in the river to me, but we call it a lake.

    There is perhaps a technical definition like when a recession ends, or whether a tomoato is a fruit or a vegetable, but it may bear little resemblance to how normal people would see it.

    I say if we call it a lake, it’s a lake.

  • kwatt

    As a native Iowan, I am not surprised.

  • Danny

    I would say its not a lake as it has a defined channel running down the middle through the length of it.

    Not sure if thats hydrological standard, but to me its what defines the character of the body.

  • John P.

    There are probably examples of this all over the place. I’m thinking right now of what they call the Temperance River flowage in the BWCA. As you canoe up that chain of long narrow lakes (Baker, Kelly, Peterson, Weird Lake, and others) you realize it is really more like a river with narrow spots and swamps restrictng it here and there. I don’t know where the cutoff is.

  • MrRetentive

    Funny you should write about this today.

    On our way home from New Ulm yesterday afternoon, I noticed on the GPS that one of the backwaters of the Minnesota River near MSP airport was named Gun Club Lake.

    So many things a person never even considers…

  • Bismuth

    //We also came to understand that many of those “lakes” are actually ponds.

    Perhaps it’s the New Englanders that have it backwards.

    From wikipedia: “Regional differences include the use of the word pond in New England, and Maine in particular, for relatively large water bodies. For example a Great Pond in Maine is considered to be at least 10 acres (41,240 m²) in area.”

    Walden Lake (61 acres) doesn’t have quite the same poetic ring though…

    As for Pepin, I’ve always thought it was a bit strange that a wide part of a river could be called a lake. But as I think about it, that’s essentially what most lakes are. The difference, I think, is that classic Minnesota lakes are typically roundish in shape (or in scientific terms, they have an aspect ratio of about 1:1) and are much, much wider and longer than the width of their feeding rivers.

    Or I suppose you could look at their formation; Lake Pepin formed by the Mississippi backing up due to sediment from the Chippewa river (Wikipedia again), whereas the classic Minnesota lake is the result of glacial action.

  • andy

    This reminds me of a funny April Fools Day prank that the local radio station (KWNG) pulled many years ago;

    The morning show said the US Army Corps of Engineers were going to redirect the Mississippi River around Red Wing so that the town would become part of Wisconsin. People were calling in not concerned with the relocation of an entire river nor the costs involved. They were mad as he!! about becoming part of Wisconsin.

    As far as this post goes however, I grew near Lake Pepin (in Wisconsin, there, I said it) and though it’s not a “lake”, I won’t call it anything but.

  • Ben Chorn

    As a geology graduate student at UMD studying limnology- I would consider it a lake.

    Lakes can be caused by damming of rivers from landslides, beavers, glacial moraines, etc. A similar example of a lake in the middle of a river was just discussed in a class- Fremont Lake in Wyoming.

  • Jon

    Should there be some consideration for what happens at the mouth of the lake/swelling/Chippawa’s drainage barrier? For example, is the river after the mouth at a lower elevation than the height of Pepin’s surface before the mouth? If all of Pepin is at the same elevation and then it drops after the mouth, that would seem to support the notion that it is a lake (given its size). Then again, I’m from a semi-arid region where lakes aren’t so common, so what do I know?

  • Ben Chorn

    The point being that not all lakes are the usual glacial, round-ish lakes we typically see scattered across Minnesota.

  • bsimon

    Two characteristics of ‘lake’ Pepin argue against its lakeness. 1) it is shaped more like a river than a lake and 2) its source of water is largely the same as its drain. As a lake purist, I’d say the idealistic lake is spring-fed, and doesn’t have a significant surface flow into it. Next would come your lakes with multiple surface inputs & one exit – for instance the great lakes. What may be an argument in favor of ‘lake’ Pepin’s lakeness is if its depth is significantly different from (i.e. deeper than) that of the river channel.

  • susie

    Well, my Scandinavian family was in Red Wing and the surrounding area before MN was a state. So I’m a native by four generations.1) It is a lake because we say it is, right? If that is the premise, well, we say it is. 2) As I remember it, there is a spring-fed lake through which The River flows. 3) There is much evidence of glacial activity, too. 4) Some of these definitions would also disqualify the Great Lakes, which seems dumb. 5) When all else fails, let’s go with the limnologist.