The Middle Fork of the South Platte River, located below Montgomery Reservoir in Colorado, is a prime destination for fly fishing enthusiasts. This section of the river is known for its scenic beauty, diverse fish species, and a variety of fishing spots ranging from serene meadows to rocky, challenging terrains. The river flows through several state wildlife areas, making it accessible and popular for both novice and experienced anglers.
The Middle Fork is currently flowing at around 43 cubic feet per second (cfs), which is lower due to a recent dry spell but within the seasonal averages. The cooler morning temperatures provide the best conditions for fishing, with increased fish activity observed during these times. It's currently hopper season, which means dry flies, especially hopper patterns, are highly effective. However, be aware of potential weather changes; heavy rain can quickly increase water levels and affect clarity, so it's wise to check the weather forecast before heading out
Here’s a breakdown of the flies and patterns that are currently producing the best results on the Middle Fork of the South Platte:
Dry Flies:
Nymphs:
Streamers:
source: Colorado Divison of Resources Station Flow Report
For real-time data on river conditions, visit the Colorado Division of Water Resources.
Blue-Winged Olive (BWO) Patterns
Patterns: Parachute Adams, Sparkle Dun, Comparadun BWO
Sizes: #18-22
When to Use: BWOs hatch consistently, especially during cooler, overcast afternoons. These flies are effective in slow-moving pools and seams where trout are rising to feed on emergers and duns.
Caddisfly Patterns
Patterns: Elk Hair Caddis, Goddard Caddis, X-Caddis
Sizes: #14-18
When to Use: Caddisflies are active in the evenings, making these patterns ideal for fishing just before dusk. Present these flies in riffles and along the banks where caddis are likely to be hatching.
Terrestrial Patterns (Hoppers, Beetles, Ants)
Patterns: Chubby Chernobyl, Amy’s Ant, Foam Beetle
Sizes: #10-16
When to Use: Terrestrial patterns are especially effective during the summer and early fall when grasshoppers, beetles, and ants are abundant. Fish these flies close to the banks and in meadow sections where trout are opportunistically feeding on terrestrials
Trico Patterns
Patterns: Trico Spinner, CDC Trico Dun
Sizes: #20-24
When to Use: Trico hatches occur in the early morning, making these flies a good choice for targeting rising trout in the slow-moving water of the meadow sections.
Pheasant Tail Nymph
Sizes: #16-20
When to Use: A versatile nymph pattern that imitates a variety of aquatic insects. It’s effective year-round and can be used in both riffles and pools, especially when there is no visible surface activity.
Copper John
Sizes: #14-18
When to Use: The Copper John is effective in faster-moving water where getting the fly down quickly is crucial. This pattern is particularly good for targeting trout in deeper runs and riffles.
RS2
Sizes: #18-22
When to Use: The RS2 is a great emerger pattern for BWO and PMD hatches. It’s best fished just below the surface, either as a dropper under a dry fly or as part of a two-fly nymph rig.
Zebra Midge
Sizes: #18-22
When to Use: Zebra Midges are effective year-round, especially in colder months or during non-hatch periods. They are best fished in slower runs and pools where trout are feeding near the bottom.
Woolly Bugger
Sizes: #6-10
When to Use: Streamers like Woolly Buggers are effective for targeting larger trout, particularly in deeper pools and around structure. They are best fished in low-light conditions or when the water is slightly off-color.
Duracell
Sizes: #16-18
When to Use: This small, beadhead streamer pattern is perfect for deeper runs and riffles. It's especially effective in clear water when fished with a slow, steady retrieve to mimic a wounded baitfish.
Dry fly and dry-dropper rigs are highly effective, especially during the late summer and early fall when terrestrial insects like grasshoppers, beetles, and ants are abundant.
Dry-Dropper Rigs: This setup is ideal for the meadow sections of the Middle Fork. A buoyant dry fly (such as a Chubby Chernobyl, Amy’s Ant, or Foam Beetle) serves as an indicator fly, with a nymph or emerger (like a RS2 or Pheasant Tail Nymph) suspended below. This rig allows you to cover both surface-feeding trout and those holding just below the surface. The dry fly can entice aggressive strikes from fish looking for terrestrial insects, while the dropper targets trout feeding subsurface
Focus on Presentation: With clear water conditions, a drag-free drift is essential. Use longer leaders (9-12 feet) and fine tippets (5x-6x) to avoid spooking fish. Cast upstream and mend your line frequently to maintain a natural presentation. Target areas where the current slows near the banks or in seams, as these are prime spots for trout rising to dry flies.
Nymphing is a reliable tactic on the Middle Fork, especially in deeper runs, riffles, and pools where trout are feeding below the surface.
Two-Fly Nymph Rig: Use a two-fly nymph rig to cover different depths and food sources. Start with a heavier attractor pattern, like a Copper John or BH Hare’s Ear Nymph, as your point fly, and add a smaller, more natural nymph like a Zebra Midge, RS2, or Pheasant Tail as a dropper. This combination allows you to target both bottom-feeding and mid-column trout
Adjust for Depth and Current: Vary the weight of your nymph rig to match the current speed and depth. In faster water, use more weight to get your flies down quickly to the strike zone. Strike indicators are useful for detecting subtle takes in the deeper, faster sections of the river.
High-Sticking Technique: In tighter sections with faster currents, high-sticking (keeping a tight line with minimal slack) is effective for targeting trout in deeper runs and pocket water. This method gives you better control over the nymphs and increases sensitivity to strikes, especially when trout are holding close to the bottom.
Streamer fishing can be very effective on the Middle Fork, particularly for targeting larger, more aggressive trout or when the water is slightly off-color due to recent rain.
Swinging and Stripping Streamers: Use streamers like Woolly Buggers, Duracell, or Zonkers to imitate small baitfish, leeches, or crayfish. Cast these flies into deeper pools, along the edges of faster currents, or near undercut banks where larger trout may be hiding. Experiment with different retrieval speeds—short, quick strips can mimic a fleeing baitfish, while slower, steady pulls can imitate a wounded prey item
Focus on Low-Light Conditions: Streamer fishing is often most productive during low-light conditions, such as early morning or late evening. It can also be effective during overcast days or when the water is slightly off-color, making trout less cautious and more likely to chase larger prey.
The Middle Fork’s clear waters often call for a stealthy approach, especially when sight fishing for trout holding in shallow runs or near the banks.
Polarized Sunglasses: Use polarized sunglasses to reduce glare and help spot fish holding in deeper pools or along the river's edges. Seeing the fish allows for targeted casting and more precise presentations, increasing the likelihood of success.
Long Leaders and Light Tippet: Use long leaders (9-12 feet) and light tippet (5x-6x) to reduce visibility and avoid spooking fish. Approach the water carefully, keep a low profile, and minimize unnecessary movements that could alert the trout to your presence.
Read the Water: Look for subtle signs of fish activity, such as bubbles, surface disturbances, or slight changes in water color that indicate seams or feeding lanes. Focus on fishing these areas thoroughly before moving on.
The Middle Fork can experience rapid changes in conditions due to weather or water releases. Adapting your tactics based on current conditions is key to success.
Stay Flexible: Be prepared to switch daily tactics based on fish behavior and water conditions. If dry flies aren’t working, switch to nymphing or streamers. Keep a variety of flies and adjust your presentation as needed.
Timing Your Outing: Early mornings and late afternoons are often the best times to fish the Middle Fork, as trout are more active and feeding. During the middle of the day, especially on hot, sunny days, focus on deeper pools or shaded areas where fish might be holding.