The Gardner River (also known as the Gardiner River) has some of the most beautiful pocket water fly-fishing stretches found throughout Yellowstone National Park. A tributary of the Yellowstone River, the Gardner is approximately 25 miles long and can be found in the Northwestern section of the park. While the fishing on the Gardner can be fast and furious, having an articulated approach to how and where you want to fish on this river will definitely increase your odds at catching quality fish.
Get Off the Beaten Path
First and foremost, if you want to catch fish on pressured waters, you have to get away from the other anglers. While the Gardner River offers some excellent curbside fishing opportunities, realize that these easily accessible spots will see increased pressure from fly anglers. Plan day trips to reach stretches of water that you know not everyone is going to fish. The Gardner River up by Mammoth is nestled between some pretty serious canyons and the hike down will deter most non-serious fisherman.
Don't Only Fish Soft Water
When most fly anglers think of fishing in Yellowstone, they think of long meadows and slowly meandering steams. While these areas do exist and hold plenty of fish, they will also host more anglers per day than any other spots. Yellowstone trout streams like the Gardner have large numbers of trout per mile and those fish spread out over the entire stream reach.
Targeting areas like pocket water or fast riffles that other anglers do not know how to fish gives you a distinct advantage. This pocket water or fast riffles can be intimidating at first glace. It is hard to believe a fish can actually feed in these types of conditions, but they do. If you plan on fishing this faster water, look for current breaks next to the banks or behind rocks to hold fish. Trout will sit in these areas and ambush prey as it floats overhead. Another good place to try in fast water is a seam where fast and slow currents meet. This transition zone is a hot spot for churning up food, and trout will feed greedily on helpless insects.
Match the Hatch
While fly anglers can catch fish using attractor patterns on the Gardner, knowing what is hatching (where and when) is your best bet to catching lots of trout. Checking in with the local fly shops or through online fishing reports is where you should start. These sources will know what is going on as far as hatches, but actually driving out to the stretch of river you plan on fishing and watching is important.
By observation you will figure out the color and size of the patterns you will need and approximately when they come off the water. If you don't see a hatch on the stretch of river you plan on fishing, don't panic. Flipping over a rock or two will tell you what is living in the river like stones and mayflies and if you can't find these, then putting on a hopper never fails. Hoppers hatch starting mid July and these patterns will work great all day long while waiting for a hatch to start.
The Gardner River boasts some of the best fly-fishing opportunities that Yellowstone National Park has to offer. Take the time to get to know the river and the hatches and you won't be disappointed.