What Lake Mathews Offers and When to Fish It

Lake Mathews is a 1,300-acre reservoir in western Riverside County, about 15 miles northeast of the city of Riverside, built as a water storage facility for the Metropolitan Water District. The lake holds largemouth bass, channel catfish, bluegill, and carp year-round, with spring and fall producing the most consistent action. Summer heat pushes fish deeper and into shade, making early morning and evening the only reliable windows. Winter is fishable but slower; water temperatures drop into the 50s, and fish move to deeper structure.

The lake sits in the Inland Empire's semi-arid climate, so expect intense sun exposure and limited shade on the water. Bring more water than you think you'll need, sunscreen rated for all-day exposure, and a hat. The reservoir's water level fluctuates with MWD demand, sometimes dramatically, which affects where fish hold and which boat ramps remain usable.

Key Takeaways

  • Largemouth bass dominate the catch at Lake Mathews, with spring spawning season (March through May) offering the most predictable fishing for both numbers and size.
  • The lake's northern arm near the inlet and the deeper channels along the eastern shore hold fish year-round, while shallow flats are productive only during cooler months.
  • Channel catfish bite best at night or in low-light conditions, especially during summer when daytime bass fishing slows; live bluegill or chicken liver work reliably.
  • Water level changes throughout the year affect boat ramp access and fish location, so check current conditions with the Lake Mathews Marina before launching.
  • No gas motors are permitted; only electric trolling motors and hand-propelled boats are allowed, which keeps the lake quiet and makes sight-fishing for bass more effective.

Largemouth Bass: Spring Spawning and Structure

Largemouth bass are the primary target at Lake Mathews, and spring is when they're most aggressive. From March through May, fish move into shallow water to spawn, and they'll strike topwater plugs, soft plastics, and crankbaits with little hesitation. Focus on the northern arm of the lake where the inlet feeds in; this area warms first and draws spawning fish early. The shallow flats along the western shore also hold pre-spawn and spawning bass during this window.

Summer bass fishing requires a shift to deeper water and structure. The eastern shore has a steep drop-off that holds fish 20 to 35 feet down. Throw soft plastics on a Texas rig or use a drop-shot with a shad-pattern bait. Fish the deeper channels and any submerged brush or rock piles you can locate. Early morning—first light until 9 a.m.—is your best bet; after that, the sun drives bass deep and feeding slows dramatically.

Fall (September through November) brings another strong bite as water cools and bass move back to shallower structure. The transition is fast; watch the water temperature. Once it drops below 70 degrees, shallow flats and the edges of weed beds become productive again. This is an excellent time for sight-fishing if you have polarized sunglasses and can read the water.

Channel Catfish and Night Fishing

Channel catfish provide a different rhythm and are most active when the sun is down. Summer nights are ideal—the water is warm, catfish are feeding, and you'll avoid the daytime heat. Fish the deeper channels and holes with live bluegill, chicken liver, or cut mackerel on a simple three-way rig or slip sinker setup. Cast out, set your rod in a holder, and wait for the rod to bend.

Catfish don't require finesse. Use heavier tackle than you would for bass, bring a headlamp or small light to see your rod tip, and be patient. A single night session can produce 5 to 15 fish depending on conditions. The lake's no-gas-motor rule means fewer boats and less disturbance, which actually helps catfish fishing by keeping the water quieter.

Tackle and Technique for Desert Reservoir Conditions

Lake Mathews' clear water and bright sun demand lighter line and natural colors. For bass, use 8- to 12-pound fluorocarbon or monofilament; 15-pound is acceptable if you're fishing heavy cover. Soft plastics in shad, green pumpkin, or natural brown patterns outfish bright colors. Topwater is effective during low-light periods—early morning, late evening, or overcast days—but switch to subsurface lures once the sun is high.

The no-gas-motor restriction means you'll be using an electric trolling motor or paddling. This is actually an advantage for sight-fishing and stalking bass in shallow water. Move slowly, keep noise to a minimum, and use polarized sunglasses to spot fish before you cast. The quiet water also makes it easier to hear catfish rods clicking or see subtle topwater strikes.

Water Level Changes and Ramp Access

Lake Mathews' water level is managed by the Metropolitan Water District and can drop 10 to 20 feet between spring and late summer. This affects which boat ramps are usable and where fish concentrate. The main launch at Lake Mathews Marina remains accessible across most water level ranges, but secondary ramps may become unusable during low-water periods.

Before you go, call the Lake Mathews Marina at the number listed on the Riverside County Parks website or check their social media for current water level and ramp status. A sudden drop can strand a boat or make launching impossible. Fish also concentrate in the deepest remaining holes during low water, which can actually improve fishing if you know where those holes are.

Seasons and Weather Patterns

Spring (March through May) is the most reliable season. Water temperatures climb from the 50s to the 60s and 70s, bass spawn, and catfish become active. Expect variable weather—some days are hot and clear, others cool and windy. Wind can make the lake choppy, but it also oxygenates the water and can trigger feeding.

Summer (June through August) is hot and slow during the day but productive at night for catfish. Daytime bass fishing is possible but requires patience and deep-water structure. Plan early-morning sessions or skip the heat entirely and fish after sunset.

Fall (September through November) mirrors spring in many ways—cooling water, active fish, and variable weather. This is an underrated season; many anglers focus on spring and miss excellent fall fishing.

Winter (December through February) is slow but fishable. Water temperatures drop into the 50s, and fish move to the deepest holes. Catfish still bite at night, and bass can be caught during midday when water is warmest, but expect fewer fish and longer waits between bites.

Facilities and Rules

Lake Mathews Marina operates a boat launch, bait and tackle shop, and rental fleet. Launching fees apply; check current rates on the Riverside County Parks website. The lake is open to the public during daylight hours, and overnight camping is not permitted on the water. Picnic areas and parking are available at the main launch site.

Fishing hours are typically sunrise to sunset, though this varies seasonally. No gas motors are allowed—only electric trolling motors and hand-propelled boats. This rule keeps the lake quiet and makes it an excellent choice if you prefer a calmer fishing environment. A California fishing license is required for anyone 16 and older.

Frequently Asked Questions

What's the best time of day to fish Lake Mathews?

Spring and fall, fish from sunrise through mid-morning or late afternoon through sunset. Summer requires early morning (before 9 a.m.) for bass or night fishing for catfish. Winter fishing is slow all day, but midday is slightly better when water is warmest.

Can I fish from shore at Lake Mathews?

Yes, shore fishing is permitted at designated areas around the lake. The northern arm and western shore have accessible spots. Shore fishing for catfish at night can be productive, though you'll have fewer location options than from a boat.

Do I need a boat to fish Lake Mathews effectively?

A boat gives you access to deeper structure and more water, but shore fishing and kayaks work. Kayaks are popular here because they're quiet, allow sight-fishing, and don't require a motor. Many anglers launch kayaks from the main ramp for a fraction of the cost of a motorboat rental.

What size bass does Lake Mathews typically produce?

Largemouth bass average 1 to 3 pounds, with occasional fish in the 4- to 6-pound range during spring. The lake is not known for trophy bass, but it produces consistent numbers of keeper-size fish and is good for learning bass fishing fundamentals.

Is Lake Mathews crowded on weekends?

Weekends see more traffic than weekdays, but the lake is never as crowded as larger Southern California reservoirs. The no-gas-motor rule keeps boat traffic lower overall. Early morning or weekday visits offer more solitude and often better fishing.