A guide to winter fish behavior in Idaho: Here’s what to catch and how to catch it

All creatures make behavioral adjustments to the winter chill. Bears hibernate. Birds fly south. And we humans — anglers included — tend to spend more time indoors.

But what about fish? Surely, they feel the cold. But without a warm den or couch to curl up in, our finned friends must fend for themselves. And for those of us crazy enough to fish in 30 degrees or venture out onto a frozen lake, it’s important to understand how cold weather effects fish behavior. Here are some observations from this lifelong angler (and armchair biologist):

Trout: Trout don’t mind the cold — in fact, they prefer it. Trout are the most common catches on ice fishing trips, and winter is my favorite season for fishing local streams like the Boise River, too. Unlike some fish, trout are willing to crush fast-moving lures in cold water. They’re also active throughout the water column — don’t overlook shallow water while ice fishing, and if you’re jigging in deeper water for other species, keeping a line or two shallow for cruising trout is a good strategy. Activity level: 9/10.

Bass: From April until October, bass are the most aggressive fish around. But when water temperatures plummet into the 40s, bass metabolisms slow to a crawl. Fisheries that produced 20-fish days in the summer can seem like ghost towns. But don’t be fooled — the fish are still there. Bass spend much of the winter glued to the bottom, but they can still be coaxed with smaller, slower presentations like drop shots, Ned rigs and finesse jigs. The bass I’ve caught ice fishing only moved about a foot to eat my lure. But if you present an easy meal, you better believe they’ll eat it. Activity level: 3/10.

Perch: Behind trout, perch are the most common species caught through the ice in Idaho. Perch spawn in early spring, so they spend the winter eating and growing. The biggest fish of the year — including Lake Cascade’s record jumbos — are almost always caught through the ice in February. Some perch are willing to chase lures in cold water. The rest of the fish school up on the bottom, but they can usually be coerced into eating tiny jigs tipped with a mealworm or grub. Activity level: 7/10.

Crappie: I’ve never had an opportunity to ice fish for crappie, but they do remain active in winter. The biggest difference is depth — schools that hang out in shallow water during spring and summer usually move out to 30-plus feet when temperatures drop. Rather than trolling or casting lures, anglers should focus on vertical jigging with small presentations. Using that strategy, many of my best trips at C.J. Strike and Brownlee reservoirs have come between November and February. Activity level: 7/10.

Bluegill: In warm water, big bluegill will crush just about anything in their path. When things cool down, they are much less active — but there’s something in their DNA that makes it really hard to say no to food. Like bass and perch, bluegill spend the winter hugging the muddy lake bottom. But drop down a worm or a micro jig — even through the ice — and they’ll usually grab it. Activity level: 6/10.

Sturgeon: Winter is a great time to fish for sturgeon. They don’t mind the cold and will happily eat various cut baits on the river bottom. Lower water levels also make prime sturgeon holes more obvious, and aquatic weeds are less of a problem during the cold months. Activity level: 8/10.

We humans tend to lower our activity level when it’s cold, too. But for those willing to bundle up and get after it, wintertime is a fun and unique season to enjoy Idaho’s great outdoors. Tight lines!

Jordan Rodriguez has been fishing Idaho waters since he was a teen. Share your fish stories, adventures and questions with him at tightlinesboise@gmail.com, or visit www.tightlines208.com for the latest local fishing reports and upcoming class offerings.

This story was originally published February 15, 2022 at 5:00 AM.