Backcountry fishing can provide some of the most memorable days a person will ever have in the outdoors. Deep in mountain ranges, there are streams, ponds, and lakes that are home to willing trout, but from lake to lake, the quality and numbers of fish can vary greatly. If you're the adventuring type and are willing to put some miles on your hiking boots throughout spring, summer, and fall, here are a few pointers you can use to up your chances at finding some great fishing.
Put in Your Time Before You Go
If you're going to be backpacking, you probably spent a good amount of time planning your routes and what gear to take. If fishing is a main part of your trip, especially if it's the focus of your trip, you'll need to really spend time before you go researching which lakes are worth your time. Just because there's blue on a map, it doesn't mean that fish are in there.
Scour backpacking forums, fishing report forums, check social media for mentions of lakes by name, and ask around. While many people are hesitant to give away their favorite fishing spots, usually you can piece together small bits of information to form a good picture of what a lake holds. Take spectacular fishing reports from a single source with a grain of salt, but also realize that many will downplay success just as often as they overstate it.
Many states have fish stocking reports easily available for public review online. Lakes that are stocked often aren't always the best places to hit, but they will definitely have fish when you go if a stocking was recent. Stocking frequency is often a result of fishing pressure or whether or not a lake suffers regular winter kill. Lakes that are never stocked should probably be avoided unless you can find confirmation that fish have been found there recently.
Know the Pieces to the Puzzle
Here's how I find lakes I want to target in the backcountry. Not all of these are hard rules, but more helpful guidelines. If a lake is able to check the boxes on most or all of these factors, you better believe I'm putting on my hiking pack and checking it out.
You don't need a deep lake for large fish. In fact, shallow lakes often hold larger fish due to an abundance of food sources at lower elevations, but at higher elevations, deep lakes help fish to avoid winter kill. In the high mountain elevations, shallow lakes are more prone to freezing solidly or for suffering dramatic oxygen loss. Lakes that freeze solid and have a high winter kill mean that, even if the lake is stocked well throughout summer, that the fish will never grow to large sizes. Deeper lakes allow fish to hold over during the winter and allow for fish to get bigger.
Source of Water
Most lakes exist as a result of one or more inlet streams, but in the high mountains many lakes might form from snowmelt or natural springs. Lakes with healthy water sources are for more stable in regards to fish populations. Lakes that rely old snowmelt alone will run dry on lean years or they might get so low that they freeze solid over the winter. Look for lakes with inlet streams, but don't limit your search to them alone.
Spring fed lakes are often a sign of hidden treasure. When a lake is made up primarily of spring water, the temperatures in the lake are more consistent, enjoy a more reliable oxygen level, and will be far more resistant to winter kill or drying up in summer. Spring fed lakes will often support better levels of aquatic bug life for fish to feast on year round, as well. If you can find a decently sized spring fed lake, mostly in regards to depth, that shows up on fish stocking reports (especially if stocking is infrequent), you're most likely onto something worth checking out. Some of the biggest fish I've ever caught in the backcountry were on lakes that have no visible inlet stream, but they were deep enough to avoid winter kill. The lake pictured below was small in surface area, but it had decent depth and was fed generously by springs. It was also home to some very large brook trout.
Surrounding Plant Life
If plant life is scare around a lake, it's hard to believe that the lake itself will be supporting much animal life. While you don't need tons of trees, grasses are a good sign. Many high mountain lakes will have boulders around them due to glaciers carving up the landscape, but among them look for signs of plant growth.
Fish really do need some sort of structure to grow. Smaller fish can do well surviving on bugs, but larger fish feed on smaller fish, and without structure they don't have many opportunities to ambush prey or rest. Some structure can come in the form of terrain, so lakes with large boulders around their shores are sure to provide good underwater cover.
Lakes that have a lot of timer on their edges are also great to check out. I've found some impressively large cutthroat and brook trout hiding just a few feet from shore that were cruising along downed trees.
Stocking reports will indicate whether or not a lake is managed as a fishery, but they don't always tell the story of how many fish or the quality of fish you might find. As mentioned earlier, frequent stocking ensures that fish will be there, but it also might indicate heavy fishing pressure or that lake's inability to maintain populations well. Infrequent stocking can indicate a few things, but you're going to have to explore a bit to find out what the story is.
A lake that isn't stocked often may do a great job maintaining its fish numbers, which would mean that you're likely to find healthy populations of fish there. On the flip side, a lake that isn't stocked often might not get tons of attention due to the difficulty in stocking the lake because of its remote location. If you call the Division of Wildlife Resources, they might offer up the answer to that question for you. The lake below shows up regularly on the DWR stocking reports, and I found it a big help. This lake is home to some healthy cutthroat, feisty brook trout, and some surprisingly large rainbows which will give you some amazing battles.
If a lake has no history of fish stocking in the high country, you're not likely to find fish there unless native fish are very common in the area and the lake has some sort of inlet and/or outlet connecting it with other waters.
Be Willing to Try Multiple Times
High mountain lakes are fickle. With wildly swinging temperatures, rapidly changing weather, and other fluctuating conditions, lakes can have off days, even when conditions seem ideal. Give a lake more than one try before you write it off. Some lakes will also have their prime time of the year earlier or later than others, especially based on their elevation. It takes a lot of patience to find the hidden gems in the backcountry, but they're well worth the effort. The lake below was a bust the first time I visited it, but it was a riot the next time and I was able to hook into some bruiser brook trout.
Keep Detailed Notes
It's a good idea to save notes about your trips into high mountain lakes and to jot down what kind of weather you had, what the wind conditions were like, the date, and the water temperatures you measured, and what flies or lures were particularly effective. It can take a few years to form up a reliable picture of what turns a lake on or off to great fishing, but it'll pay off big time for when you want to try new waters out. I keep a Google Doc that I add to after each trip.
Use Your Instincts
All these tips are just my personal rules for choosing which new lakes I want to target, and they have been a pretty good predictor of quality fisheries. As you get to know the backcountry better, you'll start to form your own set of guidelines. As conditions can vary greatly from lake to lake, stick with the personal rules you come up with and refine them as you go. I am confident, however, that using the guidelines I've laid out here that you will have far more success than randomly picking places to try or chasing the latest brag post on Facebook or a fishing forum alone. There are many sources of information out there, so much sure to use everything you can to increase your odds of success!