A Trout Angler's Most Valuable Tool

[spinner1]

In the middle of summer this hole is kept cool by a tiny spring feeding in. The cooler water has more oxygen in it and the trout will travel a along ways to find cooler water.

About 20 years ago I went on a shocking crew with the Wisconsin Department of Natural Resources. I tried to guess where the big trout would be located during the shocking. I was correct some of the time but there was something that overruled my guesses and was fairly accurate. I use it every time I fish these days.

The crew shocking also took the stream temperatures each area they shocked. Not just a general temperature sampling, a temperature was taken every 10 yards. More trout were caught in the cooler water temperature areas. The lead DNR guy told me that there was a spring nearby. It was a really tiny one and if we didn't know it was there from years past we would walk right by it. From years past shocking he knew there would be lots of fish in the area. The air temperature was 70 degrees that day.

We came up to this area he talked about. I took the temperature thirty yards downstream of the spring. We started shocking there. As we got closer to the spring the temperatures went down and the numbers of trout went up. The biggest trout shocked basically had their noses directly where the tiny spring fed in. The temperature difference from first measure to the spring differed 12 degrees. The DNR guy explained to me that springs are like magnets to trout "year round" because the springs keep a constant temperature. In hot summer weather, trout will travel hundreds of yards to areas with springs.

I asked him to elaborate more about the year round idea. Cooler water in summer carries more oxygen. The surrounding water gets really warm and the warm water can not hold as much oxygen. I was curious about the winter a little more. Those springs keep that constant temperature year round. In winter when the water temperatures are frigid the trout migrate to holes that have a spring near or in it. The springs actually make the holes warmer in winter and this attracts trout and bait fish and many invertebrates.

You need to get a decent thermometer that clips to your vest with a long cord. It needs to be a tough one that is not made of glass. I recommend the all metal ones that come in a plastic sheath with a dial on the top with big numbers on it to read. When you use them, take the temperatures about 3/4s the way to the bottom of the area you are measuring. Hang on to the top of the thermometer on the dial area so your fingers don't influence the measuring. Keep it under the water for a 10 second count.


I did a check of my log books from the last 35 years. There was one reoccurring theme throughout all those years. There were actually lots of things to ponder as I read them. My log books are fairly standardized. They go chronologically and are from the entire year. They even included closed season scouting. About 20 years ago I added stream temperatures to my log books because of my experience I had with the shocking crew.

The date is first. Trout caught and sizes is next. Every time I fish I take the stream temperature. I take the stream temperature even when scouting. If I see anything out of the ordinary I put that in too. I am still clued in to my temperature idea and look for springs feeding in during the winter. I look for breaks in iced over streams. I take the temperatures there and they are typically warmer. Some springs are not evident and feed directly in from the stream bed.

My log book also has where in the holes I caught the trout. I try to give a reason I believe the trout was located there. I don't just put big trout in there. I put all trout caught in there. After I fish a hole I some time actually go in the hole and see if my reading of the hole was correct. I get to feel out the bottom terrain and learn from the outing. This teaches me how to read a hole prior to fishing it the next time and it helps with similar holes upstream.

The log includes weather conditions and water clarity. Hatches or lack of are noted. Lures/flies used and equipment is also noted. Anyone I fish with I include in the log book. If you haven't figured it out yet? It is the log book. You can have the most expensive gear and it means nothing unless you know what you are doing prior and where to go. Log Books are the Trout Angler's Most Valuable Tool and a thermometer is a close second.


I know from my log book that there is a small spring trickling in on the right side of this hole. There is six degrees warmer water right there. This is where I want to target.

[Fly Goddess]

I was going to say, my glasses, but yours is way better..

[DG]

I found that keeping a log took away a lot of the enjoyment of fishing for me. It became work, and I found that I was going fishing to feed the log, not to have fun. And in 35 years of flyfishing I have never needed a thermometer, never felt that I was missing anything by not knowing a number. Am I less of a fisherman as a result? I certainly don't think so.

To me, a fisherman's best tool is a mind capable of paying attention to what goes on around them and adapting to the situation. If a log book and thermometer help with that, more power to you, but not everyone needs them.

[JohnScott]

... log books and thermometers are aids to some anglers in some places. Those places probably constitute a small segment of a trout angler's huge universe.

A log book doesn't exist for your first time on new water ( and, personally, that is my favorite kind of place in our huge universe ). Understanding trout and their needs and good fly selection and presentation skills are about all that count.

Some of the big freestone rivers in the Intermountain West change so much each year that anything you experienced last year is old news and of no value. The same can be said of a lot of the smaller streams that have significant runoff. Again, understanding trout and their needs and good fly selection and presentation skills are about all that count.

How about fishing the duration of a huge runoff like we had in the West this year ?? Conditions change daily and the fish are adapting and moving regularly. What you did yesterday is of no consequence.

Like virtually everything in fly anglings - it depends. If you fish the same creeks every year and they never change, or see minimal structural change, year to year, log books and thermometers have a place.

If you fish rivers like the South Fork of the Snake or the Bitterroot or creeks like Big Elk, to name just a few examples of the hundreds of trout streams out here, or take on the challenge of new water regularly, forget the log book and learn about trouts and their prey.

John

[spinner1]

tools...
many things make a good angler..
tools are part but not all.

[Fly Goddess]

I don't know, I can't tie a fly on without my glasses

[spinner1]

To me, a fisherman's best tool is a mind capable of paying attention to what goes on around them and adapting to the situation. If a log book and thermometer help with that, more power to you, but not everyone needs them.

I don't consider those a tool. Have seen lots of anglers with every fancy gadget and expensive gear and digital log books. They are ALL irrelevant without this special gift or ability you have described.

[kbproctor]

I was talking with the Ranger up at Tahosa about this very thing this morning. Tumblesom is 100% spring fed. There is no inlet. Without the dam, this would be true headwaters to a small branch of the Cache la Poudre River here in Colorado. Guess it still is. When the lake was drained a couple of years ago to repair the head gate in the dam, I was able to map a few of the springs that feed the lake. There are 4 large ones and a bunch of smaller ones. I also took temperature readings. The water coming from these springs is deep artesian water and run consistant year round at about 45*. During the heat of summer and the coldest part of winter, this is where you find the fish. During the more moderate seasons, they can be about anywhere.

It isn't just the temperature that keeps fish at these spots in the lake. Due to the oxygen rich water, there are more of the critters the fish munch on.

[Fishing Jill]

I bought a thermometer at the beginning of the summer and was surprised how much I used it when the fish weren't biting. It explained a great deal and was worth the investment. I fished for ten years without one but then again I fished for a number of years without finally getting polarized sunglasses too.

Good article. I have a fishing log but unfortunately rarely write in it. I wish I did. It's kind of neat to look back at old entries and see what I was using and where. The dates and water conditions are also worth remembering.

[Fly Goddess]

I bought a thermometer at the beginning of the summer and was surprised how much I used it when the fish weren't biting. It explained a great deal and was worth the investment. I fished for ten years without one but then again I fished for a number of years without finally getting polarized sunglasses too.

Good article. I have a fishing log but unfortunately rarely write in it. I wish I did. It's kind of neat to look back at old entries and see what I was using and where. The dates and water conditions are also worth remembering.

I agree. Same here. I did use a log religiously at first and must have made some great notes, because years later I went back to a body of water and looked at that journal and read what worked and the conditions. I read the journal because I had left it in the trailer and I was having difficulty dialing the fish. I duplicated what I had wrote and dang if it didn't work!

I don't use it as much as I should or could, but then I don't fish Woolly Buggers much either and not sure why I don't.