What Lake Siskiyou offers and when to fish it

Lake Siskiyou is a 5,600-acre reservoir in far northern California, about 10 miles north of Mount Shasta city. The lake sits at 3,188 feet elevation and stays cold year-round, which means it holds rainbow trout, brown trout, and kokanee salmon — species that need cold water to thrive. The fishing changes dramatically by season: spring and early summer bring the most consistent action as fish move into shallower water after the winter cold, fall offers excellent kokanee fishing when they spawn, and summer can be slow in the middle of the day but productive at dawn and dusk.

The lake's size and depth — it reaches over 400 feet in places — mean you need to understand where fish hold at different times of year. Unlike smaller mountain streams, Siskiyou rewards anglers who pay attention to water temperature, depth, and the time of day. The reservoir is open year-round, though access can be limited by snow in winter and early spring.

Key Takeaways

  • Rainbow and brown trout dominate spring and early summer fishing; kokanee salmon peak in fall when they move into shallower water to spawn.
  • Fish the first two hours after sunrise and the last two hours before sunset during summer, when midday water temperatures push trout deeper than most anglers can reach.
  • Trolling with small spoons and plugs works year-round; casting from shore works best in spring and fall when fish are shallower.
  • The lake has four developed boat launches and several shore-access points, but parking fills quickly on weekends during peak season.
  • Water levels fluctuate significantly — the lake is lowest in late summer and fall, which can affect launch access and where fish concentrate.

Spring and early summer: the most reliable fishing window

From late April through June, Lake Siskiyou fishes best for both rainbow and brown trout. The water temperature climbs from the 40s into the low 50s, and fish move out of the deepest water into the shallower arms and points. This is when casting from shore becomes productive — you can reach fish without a boat. Focus on the northern and eastern arms of the lake, where creeks feed in and structure holds fish.

Trolling also works well during this period. Use small spoons in silver or gold, or shallow-running plugs that mimic the lake's natural forage. Troll slowly along drop-offs and points, and pay attention to depth — fish are often 15 to 30 feet down in spring, not on the surface. If you're casting from shore, use similar lures or small spinners, and work the edges where shallow water meets deeper structure.

Spring is also when the lake's water level is highest, so all four boat launches are reliably open. The McCloud Arm launch, on the eastern side, tends to be less crowded than the main Castle Lake Road launch on the southern shore.

Summer: early morning and evening fishing

By July, the lake's surface water warms into the 60s and low 70s, and trout retreat to deeper, cooler water — often 40 to 60 feet down. Midday fishing becomes difficult unless you're trolling deep or fishing from a boat with electronics that let you locate structure. Most shore anglers find summer frustrating, but the first two hours after sunrise and the last two hours before sunset remain productive.

If you have a boat, summer is when trolling pays off. Use the same small spoons and plugs, but troll deeper and slower than in spring. Some anglers use downriggers to reach the thermocline where trout concentrate. Kokanee salmon also become active in summer, though they're not the primary target until fall. If you're shore-bound, fish the early morning bite at the northern arms or wait for evening when fish move shallower.

Summer weekends bring crowds, especially on holiday weekends. Arrive early to secure parking and a launch slot, or fish on weekdays when the lake is quieter.

Fall: kokanee salmon and changing conditions

September through October is when kokanee salmon move into shallower water to spawn, and this is the lake's most exciting fishing for many anglers. Kokanee are smaller than trout — usually 10 to 14 inches — but they're aggressive and fun to catch on light tackle. They concentrate in the northern arms and near creek mouths, and they'll hit small spoons, spinners, and even flies.

The water cools back into the 50s, and trout also move shallower again, so both species are accessible to shore anglers and small-boat fishers. Fall is also when the lake's water level begins to drop as irrigation demands increase, which can affect launch access. Check current conditions before you go — the McCloud Arm launch may become unusable if the water drops too far.

Kokanee fishing can be fast and furious, but it's also catch-and-release only in California — you cannot keep them. If you want to keep fish, focus on trout, which have a daily limit of five fish with a 16-inch minimum size.

Winter and early spring: low water and limited access

From November through March, Lake Siskiyou is at its lowest level, and snow can close roads and launch access. The water temperature drops into the 40s, and fish are deep and less active. Some anglers still fish during this period, but you need a boat and the willingness to fish deep structure. Shore fishing is nearly impossible because fish are too deep to reach.

If you do fish in winter, focus on the deepest holes and use heavier lures or downriggers. The main Castle Lake Road launch usually stays open, but the McCloud Arm and other secondary launches may be closed. Call the Siskiyou County Sheriff's Department or check the Lake Siskiyou website before making the trip — road conditions and launch status change frequently.

Boat launches and shore access

Lake Siskiyou has four developed boat launches. The main launch on Castle Lake Road (south shore) is the largest and busiest, with paved ramps and parking for trailers. The McCloud Arm launch (east side) is smaller but less crowded and offers good access to productive fishing water. The Everett Memorial Highway launch (north shore) and the Gooseneck launch (west side) are smaller and may have limited facilities depending on water level.

All launches charge a day-use fee — currently around $10 to $15 per vehicle, though this varies by season and facility. Shore access is available at several points around the lake, including a public area near the dam and informal access along some roads. Parking can be limited, especially on weekends, so arrive early or fish on weekdays.

The lake has two campgrounds — Lake Siskiyou Camp Resort and Siskiyou Lake RV Park — both with boat access and facilities. Camping is not required to fish, but staying overnight can be worth it if you want to fish the early morning bite without a long drive.

Tackle and technique for Siskiyou's cold water

Lake Siskiyou's trout respond to small, natural-looking lures. Spoons in the 1/4- to 1/2-ounce range work year-round — silver and gold are reliable, but white and chartreuse can be effective in low-light conditions. Small plugs that mimic minnows, like Rapalas or Rebels in the 2- to 3-inch range, also produce. If you're casting, spinners and small crankbaits work, and fly anglers can use small streamers or nymphs, especially in spring and fall.

For kokanee, use even smaller lures — 1/8- to 1/4-ounce spoons — and focus on flash and vibration. Kokanee are attracted to movement and light, so bright colors and fast retrieves work better than with trout. Some anglers use small jigs tipped with maggots or artificial eggs, which can be effective when fish are less aggressive.

Trolling speed matters. In spring and fall, troll at 1.5 to 2.5 miles per hour. In summer, slow down to 1 to 1.5 miles per hour to reach deeper fish. If you're shore casting, vary your retrieve speed and pause occasionally to let the lure flutter — this often triggers strikes.

Frequently Asked Questions

Do I need a boat to fish Lake Siskiyou?

No. Shore fishing is productive in spring and fall when trout and kokanee are shallow. Summer and winter favor boat anglers because fish are deeper, but shore access exists at multiple points around the lake. Parking and access can be limited on weekends.

What's the difference between rainbow and brown trout at Siskiyou?

Both species live in the lake, but rainbows are more common and more aggressive on lures. Browns are larger and more selective, often requiring smaller, more natural presentations. Browns also tend to hold in deeper water and structure, so you may not encounter them unless you're trolling or fishing deep.

Can I keep kokanee salmon?

No. Kokanee are catch-and-release only in California. You can keep rainbow and brown trout — the daily limit is five fish with a 16-inch minimum size. Check current regulations before you fish, as rules can change.

What time of year has the fewest crowds?

Winter and early spring are quietest, but fishing is difficult and road access can be limited by snow. Late April through May and September through early October offer good fishing with fewer people than summer weekends. Weekdays are always less crowded than weekends.

How deep do I need to fish in summer?

In midsummer, trout often hold 40 to 60 feet down. If you're trolling, use a downrigger or count down your lure to reach that depth. If you're shore fishing, focus on early morning and evening when fish move shallower, or fish the deepest holes near the dam.