A river runs through it—but where have the fish gone?

We all have a bucket list. We may not call it that, but we all have big things we want to do in the future..

On a fall night in 1992, I added traveling to Montana and the Blackfoot River to my list. That evening, I saw “A River Runs Through It” in a small movie theater in Carbondale, Ill.

The Montana scenery was breathtaking, with lush mountains and deep, river filled valleys. I wanted to go fly fishing—preferably with Brad Pitt’s character, who was an expert fly fisherman—and I was determined to do so one day.

Of course, I was in no hurry to get to big sky country because Montana and fly fishing weren’t going anywhere. Very few were speaking of global warming and climate change back then.

Twenty years later, as a producer for “TechKnow,” I was finally on my way to Montana, painfully aware of the fact that my destination was changing and not for the better.

They have a situation on their hands in Western Montana. The state fish, the Westslope cutthroat trout, is threatened. Water temperatures are rising across the region. The U.S. Geological Survey (USGS) as well as state Fish Wildlife and Parks officials have concluded that the rivers, streams and lakes are getting warmer. The cutthroat trout are disappearing. They have two possible explanations: Either the cutthroat trout are migrating out of the region in search of cooler waters—or the rainbow trout, which prefers warmer waters, is breeding with the cutthroat and together they are producing a hybrid trout.

The rising water temperatures are forcing the unplanned closures of these famous rivers to fishermen and tourists in order to prevent the exacerbation of the trout problem. When the waters reach a certain high temperature, the fish become stressed. Fishermen make the situation worse by further traumatizing the fish population by wading into their habitat. The temporary solution is to close the waters until temperatures drop to a reasonable level to allow for fishing. This has a very negative effect on local businesses and towns. Without fly fisherman coming to the area, tourism revenue drops dramatically.

But there is hope! Ecologists from agencies such as the USGS are studying the behavior of the cutthroat in order to determine where this fish population is going and why they have changed their behavior.

High tech instruments are required for the research. USGS ecologists use an Electro-Fisher. Worn as a back pack with an extended, handheld wand. The wand is dipped into the river. Electricity is shot into the water, which stuns, but does not harm the fish. This is a very common way to collect samples from large populations of creatures like fish. Most important, there is no permanent damage to the fish.

Before being released, the fish are weighed and measured. Next, genetic samples are taken to further “flesh out” the research. Lastly, the trout are tagged. Researchers insert a GPS chip into the underside of the fish. Like a scanner in the supermarket, when the trout swim by a marker in the river, the movements are captured and individual trout are identified and followed. Using this tracking method will help reveal important migrating and unusual trout behavior.

Although the situation has not reached dire straits, the USGS is certainly concerned about the future of cutthroat trout. Fortunately, they are actively studying the trout, collecting massive amounts of data, and are taking measures to protect these fish so that future generations will have the chance to enjoy a beautiful day on the Blackfoot River, casting lines into the crystal clear water.

Bucket list, Blackfoot River, Montana… check.

Watch "TechKnow," Sunday 7:30ET/4:30PT, to learn more about conservation efforts to save Montana's fish.