Fishing in Idaho’s Mountain Lakes: Gear, Tactics & Tips for Anglers

Mountain lakes require difficult logistics when you consider the travel and hikes required to get to them, and when you arrive there is the challenge of catching fish, right?
Fortunately, the hardest part of fishing in a mountain lake is usually getting there. Fishing tends to be pretty straightforward, so don’t overthink it. Keep in mind that these fish have a very short growing season, so they tend to be quite aggressive and active eaters. The fishing pressure in mountain lakes also tends to be light, so the fish aren’t really wary, and basic trout fishing gear and tactics are usually all you need for them. to catch.
But one thing to consider is the best way to approach the distance to throw fish, which depending on the lake can be a bit tricky and you can get wet. A pair of light, quick-drying shorts or pants and athletic sandals can come in handy so you can wade along the shore and be in a better position to do a cast.
Bring a hat and polarized sunglasses to help you spot cruising trout and protect your eyes from fishing lures and intense alpine sunshine. Mountain lake trout tend to be cruisers looking for a meal, so spotting where trout are hanging out or sailing can increase your chances of catching them and save you wasting time in open water. Also, keep in mind that trout are not evenly distributed in a lake, but concentrated in certain areas.
Whether you’re a fly fisherman or using conventional gear, you don’t need a bunch of specialized gear, flies, lures or bait for mountain lakes. You need to pack your gear, so keep it simple, portable, and preferably light.
Basic setup for fly fishing
Choose a fly rod between 8.5 to 10 feet long with a line of three to five weights, preferably a rod that breaks down into four pieces for easy travel. Longer rods are generally better because they can do longer casts to reach fish and are better for the roll cast when you’re stuck against bushy shores.
Wrap your reel with a floating fly line and rig it with a 9 to 12 foot monofilament tapered no-knot leader with a 4X or 5X tip. Trout don’t tend to be shy, so you can probably get by with a heavier tip, but the water tends to be clear, so adjust accordingly.
Your kit should include a clamp, fly float, extra tip spools, wire cutters, and a basic fly box. Alpine lakes can be great places to catch trout on basic traditional dry flies such as Adams parachutes, black ants, beetles, hoppers, or other attractive small flies. Don’t feel like you have to match a certain hatch perfectly. Flies that mimic the basic shapes of insects and are similar in size to natural flies will usually catch fish.
If the trout doesn’t pick up dry flies, try hanging a small pearl-headed nymph 2 to 3 feet below the surface of a strike indicator, or slowly strip it on a long leader. Common nymphs like pheasant tail, hare’s ear, prince nymph, zebra midge, etc. in sizes 12 to 16 are good choices. Small streamers like woolly buggers in black, brown, and olive can also be productive.
Basic setup for cast fishing
A 5-7ft long spinning rod / reel combo with light or ultralight action is a good choice. The stems should break down into two to four sections for easy travel so they can be attached to a backpack. Wind the spool with a 4 pound monofilament test line to cover most situations. Using lures is a good way to keep it simple without needing to carry bait. A few 1/16 to 1/8 ounce pouring spoons and wringers are a great option. You can also throw flies with a casting rod using a bubble or float and use the same flies mentioned above.
If you prefer bait fishing, bring barrel swivels, size 6-10 bait hooks, and a few sliding or split-shot egg sinkers to get your offering on the bottom, or hang 2 to 3 feet under a float. Traditional trout baits work well, such as worms, salmon eggs, etc. But if it’s summer and there are grasshoppers, they can be great bait for live or dead caught trout. A live grasshopper floating on the surface can be almost irresistible to a mountain lake trout.
While patience is often a virtue for anglers, don’t wait too long for a fish to bite in a mountain lake. Keep moving until you start to catch fish and focus on that area.
Where are the fish?
Trout in alpine lakes are generally foraging, so it’s much easier to find fish with a basic understanding of where trout typically hunt for food. Most of the food in alpine lakes is either lake-living insects or terrestrial insects that blow on the water from surrounding trees. Insects often hatch in shallow areas of a lake, usually 2 to 10 feet deep, where the sun can reach the bottom.
Look for the trout that roam the shores along the tree-lined banks where they might find blown ants, beetles or grasshoppers. Trout often travel the same routes in search of food, so if you see a trout swimming, there’s a nice change that they’ll come back to later. Trout like to navigate areas with some sort of structure or change in the shape of the lake. Look for points, islands or underwater bumps and sudden changes in depth from shallow to deep.
Places where a stream enters or leaves the lake are also favorite spots for trout, especially at the start and end of the season. Trout are constantly cruising around the lake, so keep moving to try new places along the shore if you’re unlucky.
When you first arrive, it is often beneficial to find a highlight where the sun is behind your back and actively search for fish before you start fishing. You might be surprised at how easy they are to spot from a good point of view.
floating mountain lakes
Floating obviously has its advantages, but you must bring your boat to the lake. Fortunately, there are lightweight float tubes that are relatively easy to store, but remember that you will need a pair of fins to propel yourself up and probably some waders, as mountain lakes are cold by nature. You probably don’t want to be in a float tube with your bare legs for hours in the water. This is a good recipe for hypothermia.
Another option is a “pack raft” which is a very light and compact craft for easy transport. These specialized boats can be paddled, or you can just paddle, drift and fish. Raft packs tend to be pricey, so be prepared for sticker shocks, but they were designed specifically for mountain lake fishing, and if that’s something you plan to do a lot, they can be a good investment.
Another option is a small, inexpensive inflatable raft. Be careful of direct sunlight, especially in hot weather, as as the day warms the air can expand and cause a seam in the raft to burst. This applies to all inflatables, but even more so to inexpensive ones.
Other things to consider
Mountain lakes are amazing places, but they can also be unforgiving and the weather can be extremely unpredictable. Rainstorms can strike unexpectedly, and even snowstorms in the summer. Always pack warm clothes and possibly light rain gear, or some kind of shelter from the rain (like a light tarp or poncho), even if the day seems hot and sunny.
Bringing a multi-tool pocket knife comes in handy on the trail and should be part of your kit. These pocket knives are perfect for fishing to remove hooks and cut line, as well as making snacks or cleaning a fish for dinner. If you plan on keeping fish, a spar can be handy for storing your catch. If you plan to hike with fish, bring a sturdy plastic bag to store your fish inside and try to keep them cool during transport and have a cooler wait in your vehicle.
To find out more see our Alpine Lakes webpage, which includes information on where to go, how to prepare for your trip, fisheries management, and more.