What Lagerman Reservoir offers and who should fish it

Lagerman Reservoir is a shallow, murky impoundment in Weld County near the town of Johnstown, about 40 miles north of Denver. It holds walleye, northern pike, and catfish in water that rarely exceeds 20 feet deep and often runs turbid from wind and agricultural runoff. The lake is best for anglers targeting walleye in spring and fall, or for pike hunters willing to work shallow cover. Summer can be productive for catfish. If you want clear-water sight-fishing or a scenic mountain backdrop, this is not your destination — Lagerman is a working agricultural reservoir with a utilitarian feel, and the fishing reflects that.

The reservoir sits on public land managed by Colorado Parks and Wildlife, with a boat ramp and day-use area on the south shore. Access is straightforward, but the shallow basin and heavy silt mean you need to understand the seasonal patterns and bottom structure to catch fish consistently. Most anglers fish from boats; shore access exists but is limited and less productive.

Key Takeaways

  • Walleye fishing peaks in spring (April through May) and fall (September through October) when fish move into shallower water and feed more actively.
  • The reservoir averages 12 to 15 feet deep with a soft silt bottom, so use sonar to locate the few deeper holes and structure where fish concentrate.
  • Northern pike are present year-round and respond well to large swimbaits and spinnerbaits worked along the shallow weed edges and drop-offs.
  • A Colorado Parks and Wildlife Parks Pass is required for day-use parking; purchase one at the entrance station or online through Colorado Parks and Wildlife.
  • Catfish bite best in summer evenings and at night using chicken liver, cut shad, or stink baits anchored near the dam or deeper holes.

Seasons and when fish are most active

Spring (April through May) is the strongest season for walleye at Lagerman. As water temperatures climb from the low 40s to the mid-50s, walleye move out of the deepest basin and into the shallower flats to feed. Dawn and dusk are prime times, but overcast days can produce all day. Jigs tipped with live minnows or soft plastics work best; cast along the shallow edges where the bottom transitions from 8 to 15 feet. The water is usually clearer in spring than later in the year.

Summer (June through August) is slower for walleye but excellent for catfish. Walleye retreat to the deepest holes — typically near the dam — and become less active in the heat. Catfish, however, feed aggressively in warm water, especially at night. Fish the deeper holes and the dam structure with cut bait or chicken liver on the bottom. Pike remain scattered but are less predictable in summer; focus on early morning and late evening.

Fall (September through October) rivals spring for walleye fishing. As water cools back into the 50s and 60s, walleye return to the shallows and feed heavily before winter. The same jig-and-minnow tactics work, and the bite often extends into midday. Pike also become more aggressive in fall as they feed up before winter. Northern pike fishing can be strong through November if the lake does not freeze early.

Winter (November through March) is possible but challenging. The lake can freeze solid by December, closing boat access. If open water persists, walleye fishing slows dramatically and requires patience and deep-hole fishing near the dam. Many anglers skip Lagerman in winter and fish other Colorado reservoirs with better winter conditions.

Species present and what tackle to bring

Walleye are the primary target and the most consistent fish at Lagerman. They range from 12 to 20 inches, with occasional fish to 24 inches. Fish jigs (1/4 to 1/2 ounce) tipped with live minnows, shiners, or soft plastics like 3-inch paddletail swimbaits. Jigging is more effective than casting because the water is murky and fish rely on vibration and feel. Bring a sonar unit — it is not optional at Lagerman. Walleye suspend over deep holes and along subtle bottom transitions that are invisible without electronics.

Northern pike are abundant and aggressive. Most run 18 to 28 inches, with occasional fish to 35 inches. Pike respond to large swimbaits (4 to 6 inches), spinnerbaits (1/2 to 1 ounce), and large soft plastics. Cast along weed edges, shallow drop-offs, and any visible structure. Pike fishing is more visual and reactive than walleye fishing, so you can cover water faster. Use a wire leader or heavy fluorocarbon to prevent bite-offs.

Catfish (channel catfish, primarily) are present and underutilized. They run 12 to 30 inches and bite best in summer and early fall, especially at night. Use a basic catfish rig: a three-way swivel with a sinker on one leg and a 2/0 to 4/0 circle hook on another. Fish chicken liver, cut shad, or commercial stink baits. Anchor near the dam or in the deeper basin and wait. Catfish fishing at Lagerman is straightforward and can be productive if you target the right season.

Access, parking, and day-use requirements

Lagerman Reservoir is accessed via County Road 13, which branches north from Highway 34 near Johnstown. The drive from Denver takes about 50 minutes. The day-use area is on the south shore and includes a paved boat ramp, parking lot, and vault toilets. There is no fuel, food, or lodging at the reservoir, so bring what you need.

A Colorado Parks and Wildlife Parks Pass is required for day-use parking. A daily pass costs a set amount (check the Colorado Parks and Wildlife website for current pricing) and can be purchased at the entrance station or online in advance. An annual pass is also available and covers all Colorado Parks and Wildlife day-use areas statewide. The entrance station is staffed during daylight hours; if you arrive early or late, self-pay envelopes are available.

Boat ramps are well-maintained but can be crowded on weekends during spring and fall. Arrive early if you plan to fish peak times. The ramp accommodates trailers up to about 20 feet. Jet skis are not allowed. Fishing from shore is possible along the south shore near the parking area, but boat access is strongly recommended because most productive water is away from shore.

Regulations and licensing

Colorado fishing requires a fishing license for anyone 16 and older. Licenses are available online through Colorado Parks and Wildlife, at sporting goods stores, or at the entrance station. A one-day license is available if you do not want to commit to a longer term.

Walleye have a daily bag limit of 5 fish with a 15-inch minimum size. Northern pike have a daily bag limit of 5 fish with a 24-inch minimum size. Channel catfish have a daily bag limit of 25 fish with no minimum size. These limits are current as of this writing but can change; check the Colorado Parks and Wildlife website or the current fishing regulations brochure before you fish.

Catch-and-release fishing is allowed and encouraged for pike if you want to preserve the population. Walleye are good table fare and many anglers keep them. Catfish are also edible and popular in some regions. Use barbless hooks or pinch down barbs to reduce injury if you plan to release fish.

What to bring and how to prepare

Bring a boat or plan to fish with someone who has one. A 16 to 20-foot boat with a 40 to 60-horsepower motor is ideal; the shallow water and silt bottom mean you do not need a large, expensive rig. A sonar unit (fish finder) is essential for walleye fishing and highly recommended for pike. Even a basic unit will show bottom structure and help you locate deeper holes where walleye concentrate.

Pack extra tackle because Lagerman's silt bottom and snags claim lures. Bring jigs in 1/4, 3/8, and 1/2-ounce weights, a variety of soft plastics, spinnerbaits, and swimbaits. Live minnows are the best walleye bait; bring a bait bucket or aerated cooler. If you plan to fish catfish, bring a basic three-way rig setup and stink baits or cut bait.

Wear polarized sunglasses to spot pike and shallow structure. Bring sunscreen, a hat, and water — the reservoir is exposed with little shade. Wind is common, especially in spring and fall, so dress in layers. If you fish in summer, bring insect repellent; mosquitoes can be heavy near the shore.

Nearby alternatives if Lagerman does not fit your plans

Boyd Lake State Park, near Loveland about 30 miles south, is another shallow reservoir but offers better facilities, more consistent walleye fishing, and a campground. It is busier and more developed than Lagerman.

Horsetooth Reservoir, west of Fort Collins, is larger and deeper with clearer water and a stronger pike population. It requires more travel from Denver but offers better scenery and more diverse fishing options.

Jackson Lake State Park, northeast of Fort Morgan, is a larger impoundment with walleye, pike, and perch. It has more amenities and is less turbid than Lagerman, though it is farther from Denver.

If you want a mountain lake with clear water and trout, Granby Lake or Shadow Mountain Lake in the North Central Mountains are worth the drive, though they are 90 minutes or more from Denver and require different tackle and techniques.

Frequently Asked Questions

Is Lagerman Reservoir good for beginners?

It can be if you have access to a boat and are willing to learn sonar. The walleye fishing is straightforward — jig and minnow — but the murky water and lack of visible structure mean you need electronics to find fish consistently. Pike fishing is more forgiving because pike are aggressive and visible in shallow water. Shore fishing is difficult for beginners.

Can I fish Lagerman without a boat?

Shore access is limited and less productive. Most fish are in deeper water away from the shoreline. If you do not have a boat, consider hiring a guide for a day or fishing with someone who does. Alternatively, Boyd Lake or Horsetooth Reservoir have better shore-fishing opportunities.

What is the best time of day to fish Lagerman?

For walleye, dawn and dusk are most productive, especially in spring and fall. Overcast days can produce all day. For pike, early morning and late evening are best, but pike can bite throughout the day if you find structure. Catfish bite best at night in summer.

Do I need a guide to fish Lagerman successfully?

A guide is not required but can accelerate your learning curve, especially if you are unfamiliar with sonar or shallow-water walleye fishing. Local guides operate on the reservoir and can teach you where fish concentrate and how to read the bottom structure. Many anglers fish Lagerman successfully on their own after one or two trips.

What should I do if the water is very turbid?

Turbid water is normal at Lagerman, especially in spring and after wind events. Fish rely more on vibration and lateral-line detection, so use larger lures and jigs that create more movement. Darker colors (black, purple, dark green) are often more visible than bright colors. Sonar becomes even more important because you cannot see structure or fish visually.