Crystal clear

I disagree with it some Clearwater lake up the Gunflint the MN DNR Fisheries secchi-disc used by DNR, they could see down 28 feet.
Yes, the article relied on Satellite imagery-so different methods.

Yeah I think those numbers are a bit off. Or at least there are lakes with better clarity than the top ten they have listed. Clearwater was my first thought as well. Also another that came to mind is Crystal Lake (also off the gunflint) is over 18'.

I've always heard Indiana lake mentioned as being exceptionally clear, so I'm surprised it's not on the list.

NEIowapaddler: "I've always heard Indiana lake mentioned as being exceptionally clear, so I'm surprised it's not on the list. "

+1

NEIowapaddler: "I've always heard Indiana lake mentioned as being exceptionally clear, so I'm surprised it's not on the list. "

I agree. Almost every time I read about Indiana Lake, there is mention of how clear it is.

Mike

Ester is a beautiful lake, but my memory of it is that it had a glacial tinge to it that could impact clarity. Hanson for sure did. I'll find out first hand in a couple days.

There is a Clearwater Lake south of Lake One. This is the clearest lake I have ever seen. Like a swimming pool.

Traveler: "There is a Clearwater Lake south of Lake One. This is the clearest lake I have ever seen. Like a swimming pool."

i AGREE

I disagree with their methods for loads of reasons, namely that every lake changes by the day and an accurate measurement would measure every lake every day from a dozen or more points in the lake. At the end of the day, the lakes which made the top ten likely made it by a matter of inches which further "muddies the waters" as to the validity of the list. For example, take the fact that Clearwater (the eastern one) isn't on the list. The value they used was from what they call an annual mean which rated 2008 as a clarity of 11.9 feet. They used 2008 because it was the data they had the most consistently across the study area. However, in Clearwater's case it was the second lowest annual mean recorded for the lake. For whatever reason, Clearwater was less clear that year. In comparison, the average of all of their data for Clearwater across time was 14.9 feet of water clarity, a number which would stick it third on the list. Because they cherry picked from one year, a strategy which means some lakes are clearer or more opaque than their average due to annual weather, winter variables, pollen loads from their surrounding forests, smoke and debris landing in water based on wind directions that year, or a million other variables, this list is invalid. This article should be "clearest lakes in the BWCA in 2008."

And to me, even more egregious is the the fact that Basswood made the 500-acres list discredits the entire study. 12.5 ft of water clarity? Where did they cherry pick that number from!?! Sure, maybe out in open water on the Canadian side, but if one were to take an average of the whole lake (what the numbers infer) then they would have to include Hoist and Back Bays too. Which lakes over 500 acres didn't make the list, one might ask? For starters, Saganaga. Dark water, but can't be worse than Basswood can it? Big notables though were Little Saganaga, both Clearwaters, Winchell, Pine, Mountain, Gabi, Tuscarora, Rose, and Daniels, all lakes over 500 acres, did not make the lakes over 500 list. By that inference, Basswood is clearer than those lakes?!?! Not in any world is that true. As it is, their own data discredits them. The 2008 annual mean from the data set they claimed to use puts Basswood at 7.13 feet of water clarity. The highest number ever recorded for the lake is much higher, back in the 90s, but it has been hanging just below 10 ft most of the last decade.

My guess is that the article title is "ten clearest lakes," but that the study chose a list of study lakes to monitor. They likely chose lakes throughout the BWCA to get an good general study area. Thus the article should be "ten clearest lakes that the university studied" not "ten clearest in the BWCA." If it was 10 clearest in the BWCA, one would see it pretty heavily lean towards the far eastern side with a few trout lakes on the far western end and in the area around and south of Knife/Kekekabic.

As it is, this article is completely false because of the title. The annoying thing is that it is going to get quoted for years to come just like the "largest and deepest lakes in the BW" "facts" that one finds around the internet. Sigh.... Keep fighting the good educating fight I guess. Haha!

TreeBear: "I disagree with their methods for loads of reasons, namely that every lake changes by the day and an accurate measurement would measure every lake every day from a dozen or more points in the lake. At the end of the day, the lakes which made the top ten likely made it by a matter of inches which further "muddies the waters" as to the validity of the list.


And to me, even more egregious is the the fact that Basswood made the 500-acres list discredits the entire study. 12.5 ft of water clarity? Where did they cherry pick that number from!?! Sure, maybe out in open water on the Canadian side, but if one were to take an average of the whole lake (what the numbers infer) then they would have to include Hoist and Back Bays too. Which lakes over 500 acres didn't make the list, one might ask? For starters, Saganaga. Dark water, but can't be worse than Basswood can it? Big notables though were Little Saganaga, both Clearwaters, Winchell, Pine, Mountain, Gabi, Tuscarora, Rose, and Daniels, all lakes over 500 acres, did not make the lakes over 500 list. By that inference, Basswood is clearer than those lakes?!?! Not in any world is that true.


My guess is that the article title is "ten clearest lakes," but that the study chose a list of study lakes to monitor. They likely chose lakes throughout the BWCA to get an good general study area. Thus the article should be "ten clearest lakes that the university studied" not "ten clearest in the BWCA." If it was 10 clearest in the BWCA, one would see it pretty heavily lean towards the far eastern side with a few trout lakes on the far western end and in the area around and south of Knife/Kekekabic.


As it is, this article is completely false because of the title. The annoying thing is that it is going to get quoted for years to come just like the "largest and deepest lakes in the BW" "facts" that one finds around the internet. Sigh.... Keep fighting the good educating fight I guess. Haha!"

Maybe Washinton bay of Basswood, otherwise no.

Totally agree with all of this. I have hopes of one day doing a scuba trip and will monitor Secchi dish data to identify lakes that would take little or no portaging to get to while being as clear as possible. Clearwater has always been the one that seems to jump out as meeting this criteria....with possible day trips with a tank or two up to Mountain.

The prospect of portaging scuba gear and a dozen tanks to any lake on this list is not what I would call inviting.

Cricket67: "Totally agree with all of this. I have hopes of one day doing a scuba trip and will monitor Secchi dish data to identify lakes that would take little or no portaging to get to while being as clear as possible. Clearwater has always been the one that seems to jump out as meeting this criteria....with possible day trips with a tank or two up to Mountain.


The prospect of portaging scuba gear and a dozen tanks to any lake on this list is not what I would call inviting. "

Lot of people dive at the mine pits at Crosby-secchi disc reading close to 40 feet.

I would have to agree with what most people have mentioned. Seemed like they picked these lakes out of a hat full of just a sampling of regular to clear lakes in the BWCA.

Interesting to consider these issues. I found carefully inspecting the figures in that SQWN article illuminating. Moose Lake is not bad in relation to other BWCA lakes, which is interesting given the number of boats running up and down the chain.

If you read this paper from 2008, which was based on 10,500 lakes and seems to include at least the beginning of the methods used for this recent report in SQWN, the approach is impressive:

Leif G. Olmanson, Marvin E. Bauer, Patrick L. Brezonik, A 20-year Landsat water clarity census of Minnesota’s 10,000 lakes, Remote Sensing of Environment, Volume 112, Issue 11, 2008, Pages 4086-4097, ISSN 0034-4257, https://doi.org/10.1016/j.rse.2007.12.013.

This paper is listed as a reference at the end of this SQWN story.

The scientists say such information is a snapshot, so you might be able to blame the author of this piece for SQWN for lack of clarity, but perhaps not the scientists. Although we don't know what the scientists said to the reporter. I also don't see a recent peer reviewed paper that can account for this SQWN piece, but that does not mean it doesn't exist. Maybe the reporter or the scientists frequent these messageboards and can clarify things.

For sure, every measurement approach has its problems. That 2008 paper is based on a 20 year database, so they know something about stability of measurements as well as seasonal and annual variations. Two things impressed me:

1. The satellite and Secchi data were very similar, the correlation between the two being on average above .90, which is close to a straight line given the max possible is 1.0.

2. Maybe I am wrong about this, but it also sounds like lakes, on average, maintain their rank ordered clarity in relation to each other over seasons. So from spring to late summer, lakes will become more opaque, but they tend to do so at something approaching the same rate.

Alternatively, the scientists and the reporter might have screwed this up and given the public, that would be us, muddy information. But I am inclined to give people the benefit of the doubt unless there is good reason not to do so.

The clearest lake I've seen up there is Ahsub.

Swim underwater with a pair of swim goggles and look back towards the sun. You will be amazed at all the particles suspended in the water. After doing this, I won't drink unfiltered water even from clear lakes like Ester.

JELASCH: "Swim underwater with a pair of swim goggles and look back towards the sun. You will be amazed at all the particles suspended in the water. After doing this, I won't drink unfiltered water even from clear lakes like Ester. "

49 years, of tripping there
I have never filtered water

Sema Lake