Lost Valley Reservoir Depth Map & Fishing Spots (ID)

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Lake depth chart

Lost Valley Reservoir, ID

Max 21 ft

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Where to start

Callibaetis (Speckled Dun) window is on — see the hatch outlook

Hatch outlook

Callibaetis (Speckled Dun)Active window

Typical here: Aug 15 – Sep 15 · the smaller fall brood

nymphthe hours before the midday emergence — nymphs rise off the weed tops in a vertical zigzag that can take hours — sources split between slow 2–4 inch strips with long pauses and a quicker steady retrieve; carry both speeds
dunmidday, roughly 11am into early afternoon
spinnermid-to-late-morning falls

Trout browse the weed-bed edges knocking nymphs loose, then cruise the flats sipping duns at midday — the marquee western lake mayfly.

The midday emergence puts cruisers over weed flats in under 20 ft: a casting bubble with a #14 Callibaetis nymph retrieved dead-slow with pauses is the honest match. Between hatch hours, small spoons and #1 inline spinners along the weed edges and drop-offs pick off the same fish.

The event happens over weed flats and weed-bed edges in 20 ft of water or less

Chironomids (stillwater midges)Active window

Typical here: May 1 – Oct 31

nymphearly morning, start of the day — fish the bloodworm ON the bottom — 4–6 inches off the mud before the emergence starts
pupathe cool morning hours are prime — as the emergence builds, slide the pupa up to 12–15 inches off bottom under the indicator; a little wind chop does the jigging

Concentrates by DEPTH BAND and mud type, not a fixed spot: roughly 20–25 ft in spring, deeper midsummer, in against the feeder creeks in summer heat, 5–25 ft in fall. Match the band.

This one translates almost perfectly: a slip float with a 1/64–1/100 oz midge-pattern jig set 4–15 inches off bottom over a mud flat, dead-sticked with the chop doing the work. Depth control is everything — no moving lure imitates a hanging pupa; the float rig IS the technique.

The event happens over open mud flats alongside weedlines, channels and basin edges; feeder-creek mouths in summer heat

Water boatman fall flightsActive window

Typical here: Aug 25 – Oct 10 · peaks on crisp, bright fall days after the first cold snap

adultmiddday-ish on calm, sunny fall days — the fishable moment is the splashdown: boatmen dive in headfirst trailing an air bubble and make repeated trips back to the surface — a fly or lure that dives nose-first on the drop imitates exactly this

Takes are seldom subtle — trout ravage boatmen as they hit the water and during their subsurface runs.

Tailor-made for hardware: a small 1/16 oz silver-bellied spoon or jig cast AT the rings of a splashdown sinks headfirst exactly like the natural — twitch-pause it back through the top few feet. On flight days fan-cast the shallow weed margins.

The event happens over near-shore shallows, weed beds and shoal margins on calm sunny fall afternoons

Grasshoppers (east-side summer)Active window

Typical here: Jun 15 – Sep 30

adultall day in high summer, best when afternoon wind knocks bugs onto the water

Pulls fish to the windward grassy banks and edges for months — fish the bank the wind blows ONTO.

The friendliest crossover of the summer: on lakes, drift the windward bank with a bubble-and-foam-hopper — the bubble's splash doesn't hurt a hopper presentation. On rivers, the same rig dead-drifted along the undercut grass banks, or small gold spinners under the banks between rises.

The event happens over grassy banks, undercut edges and windward shorelines

Next on this water

Damselfly migration · forageMay 15 – Jul 31 · in ~8 months

Recommendations come from depth structure and seasonal species behavior. Treat them as a starting point, not a guarantee. Contours on this water are approximations. Never use for navigation. Always check local regulations.

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Recent catches at Lost Valley Reservoir

Shared by DepthScout anglers. Exact spots stay private, always.

No shared catches here yet — be the first.Log a catch from the map above and share it to put Lost Valley Reservoir on the board.

Fishing Lost Valley Reservoir: what the data says

523-acre reservoir near Adams. The lake tops out around 21 ft. This chart interpolates between a real shoreline and a known maximum depth. It will point you at likely water, but it is not a navigation product. Every species below gets its seasonal read from the same numbers driving the chart.

There are 5.8 miles of drawn shoreline to work. With a 1.6 development index there's bank structure worth casting at, in moderation. Roughly 83% of the water is 15 ft or less as modeled, the band where the food chain lives. End to end it runs roughly 2.3 mi, about 1 mi across. It sits in Adams County. Its nearest charted neighbour, Goose Lake, is 16 mi to the northeast.

Cutthroat Trout fishing at Lost Valley Reservoir

In spring, cutthroat trout run shallow here, mostly 3 to 15 ft. Midsummer fish sit out in 6 to 21 ft before dropping to 5 to 21 ft for winter. Summer cutthroat trout concentrate at Break off the point, a prime-rated drop-off around 9 ft. Fish it in early morning and the evening and you'll meet the bite. You won't need more than a trolled spoon (small) or an inline spinner most summer days.

Season	Depth	Best window	Start at	Go-to baits
Spring	3 to 15 ft	dawn & dusk	Main-lake point (8 ft)	Inline spinner (silver/gold), Small spoon
Summer	6 to 21 ft	dawn & dusk	Break off the point (9 ft)	Trolled spoon (small), Inline spinner
Fall	4 to 21 ft	dawn & dusk	Main-lake point (8 ft)	Casting spoon, Inline spinner
Winter	5 to 21 ft	dawn	Break off the point (9 ft)	Small jigging spoon, Marabou jig

Rainbow Trout fishing at Lost Valley Reservoir

Spring rainbow trout on Lost Valley Reservoir hold shallow, usually 5 to 20 ft. By summer they slide out to 6 to 21 ft, and by winter most fish are in 4 to 21 ft. The chart's best answer is Break off the point — drop-off, 9 ft, prime for winter. Prime time lands in early morning and the evening. The summer box starts with a dodger + spoon (deep troll) or a flutter spoon.

Season	Depth	Best window	Start at	Go-to baits
Spring	5 to 20 ft	dawn & dusk	Main-lake point (8 ft)	Inline spinner (silver), Small spoon
Summer	6 to 21 ft	dawn & dusk	Break off the point (9 ft)	Dodger + spoon (deep troll), Flutter spoon
Fall	6 to 21 ft	dawn & dusk	Main-lake point (8 ft)	Casting spoon, Jerkbait over shoals
Winter	4 to 21 ft	dawn	Break off the point (9 ft)	Jigging spoon, Tube jig (white)

Chinook Salmon fishing at Lost Valley Reservoir

Come spring, look for chinook salmon tight to the bank in 3 to 21 ft. Through summer count on 6 to 21 ft; the winter hold is 6 to 21 ft. Start at Deep basin. It's a deep basin holding about 18 ft of water and rates prime come summer. Prime time lands in early morning and the evening. A flasher + fly (green/white) or a magnum spoon on downrigger is the honest summer answer here.

Season	Depth	Best window	Start at	Go-to baits
Spring	3 to 21 ft	dawn & dusk	Break off the point (9 ft)	Trolled spoon (orange/gold), Stickbait off planer boards
Summer	6 to 21 ft	dawn & dusk	Deep basin (18 ft)	Flasher + fly (green/white), Magnum spoon on downrigger
Fall	4 to 21 ft	dawn & dusk	Break off the point (9 ft)	J-plug (glow), Flasher + fly
Winter	6 to 21 ft	midday	Deep basin (18 ft)	Small spoon on a slow troll, Stickbait deep

Notable structure

Count 6 structure marks on this chart. The deepest, Deep basin, sits near 18 ft.

Deep basin: deep basin, around 18 ft
Break off the point: drop-off, around 9 ft
Main-lake point: point, around 8 ft
Secondary point: point, around 8 ft
Shallow bay flat: weed flat, around 3 ft
Back-bay flat: weed flat, around 3 ft

Lost Valley Reservoir stocking report

Date	Species	Count	Size
May 29	Rainbow Trout	—	~13"
May 12	Rainbow Trout	—	~13"

Source: Idaho Fish & Game stocking records, retrieved 2026-09-03.

Lost Valley Reservoir fishing regulations

Season dates, license requirements, and size and bag limits for Idaho waters are set by the Idaho Fish and Game — and special regulations can apply to Lost Valley Reservoir specifically, so confirm the current rules before you fish.

Check the official Idaho fishing regulations →

Common questions

How deep is Lost Valley Reservoir?

Lost Valley Reservoir is about 21 ft (6 m) deep at its deepest point. The contours here are modeled from the water's real shape and maximum depth, so treat them as a rough guide.

What fish are in Lost Valley Reservoir?

Anglers target cutthroat trout, rainbow trout, chinook salmon on Lost Valley Reservoir.

Where is the best fishing spot on Lost Valley Reservoir?

Break off the point is the top-rated area: a drop-off in about 9 ft of water that rates prime for cutthroat trout in summer. The interactive chart above rates every spot for each species and season.

When is the best time to fish Lost Valley Reservoir?

For cutthroat trout, the summer bite is best in early morning and the evening. Each species page section below lists the seasonal windows, and the map shows a live NOW badge when you're inside one.

Is Lost Valley Reservoir stocked with fish?

Yes — per Idaho Fish & Game stocking records records, Lost Valley Reservoir was most recently stocked May 29 with rainbow trout. The full stocking history is listed above.

What are the fishing regulations for Lost Valley Reservoir?

Fishing on Lost Valley Reservoir is regulated by the Idaho Fish and Game. Check the official Idaho regulations for current license requirements, season dates, and size and bag limits — special regulations can apply to this specific water.

Nearby waters

Goose Lake 16 mi · Hornet Reservoir 18 mi · Payette Lake 21 mi · Blackwell Lake 23 mi · Upper Payette Lake 24 mi · Cascade Reservoir 30 mi · Brownlee Reservoir 40 mi, ID/OR · Ice Lake 43 mi, OR · Mann Creek Reservoir 45 mi · Sage Hen Reservoir 46 mi · Deadwood Reservoir 60 mi · Malheur Reservoir 73 mi, OR

See how Lost Valley Reservoir stacks up: best rainbow trout lakes in Idaho · best chinook salmon lakes in Idaho · best cutthroat trout lakes in Idaho

Browse all Idaho fishing maps or see every water on DepthScout. How we build these maps. Fish here with a sonar unit that logs? Send us your depth data and we'll improve this chart, credited to you. For fishing guidance only, never navigation.