Idaho · Fishing
Fishing in Firth, Idaho
Firth sits in the upper Snake River Plain of eastern Idaho, and the fishing around it pulls from two distinct types of water.
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Firth sits in the upper Snake River Plain of eastern Idaho, and the fishing around it pulls from two distinct types of water. Blackfoot Reservoir to the northeast is the area's biggest draw — a large impoundment known for yellow perch and rainbow trout, where bank fishing is genuinely productive and boat ramps give you access to open water. Rat Lake is a smaller, quieter option that sees less pressure and can fish well for those willing to explore. On the moving-water side, Trail Creek Bridge Campground and Graves Creek Campground both put you right on river fishing, with the added convenience of being able to camp where you fish. The rivers in this corridor run through sagebrush and farmland terrain, so expect open banks and variable flows depending on irrigation season. This isn't remote wilderness fishing — access is generally straightforward, crowds are light outside of summer weekends, and you don't need a boat to have a good day. If you're driving up from Idaho Falls or coming through on a longer eastern Idaho loop, the variety here — reservoir, small lake, and two river access points — makes it worth building a half-day or full day around.
Frequently asked questions
What kinds of fish can I target around Firth?
Blackfoot Reservoir holds yellow perch and rainbow trout and is the most consistent producer in the area. Rat Lake and the river access points at Trail Creek Bridge Campground and Graves Creek Campground can hold trout as well, though conditions vary by season and water levels. Check Idaho Fish and Game's current stocking reports before your trip to know what's been recently added.
Do I need a boat to fish Blackfoot Reservoir?
No. Bank fishing at Blackfoot Reservoir is a real option, particularly for perch, which tend to school near structure and shallower areas. A boat or kayak opens up more of the water and lets you move around, but plenty of anglers do fine from shore.
When is the best time of year to fish here?
Late spring through early summer is generally strong for trout in both the reservoir and the river access points, before water temperatures climb. Perch fishing at Blackfoot Reservoir can hold up well into summer and even into fall. River flows at Trail Creek and Graves Creek are influenced by irrigation drawdowns, so late summer can mean lower, warmer water — worth checking conditions before you go.
What's the best time of day to fish?
Early morning is consistently the most productive window, especially in summer when midday heat pushes fish deeper or into slower water. Evening can also be good on the reservoir. Midday fishing in July and August tends to slow down noticeably.
Can I camp at the fishing spots?
Yes. Trail Creek Bridge Campground and Graves Creek Campground are both listed as river fishing access points with camping, so you can set up and fish the same water. Blackfoot Reservoir also has camping options in the area. Arriving on a weekday gives you a better shot at a site during summer.
