Fly Fishing Tips 3 min read

How To Fish An Undercut Bank with Terrestrials

Ken Sperry

Posted by Ken Sperry

March 30, 2024

How to fish an undercut bank with terrestrials.

Matt Wilhelm, with Yellowstone Fly Fishing School in Livingston, Montana, and Montana Angler in Bozeman, Montana, explains how to fish undercut banks with terrestrials.

Terrestrial fly fishing offers unique and exciting challenges for anglers seeking to outsmart trout and other freshwater fish. Techniques specific to using imitations of grasshoppers, ants, crickets, and beetles can lead to success, especially when fishing an undercut bank.

Fish seek refuge in this natural shelter and await their next meal. Currents eroding beneath the banks create these formations, which vary in depth and provide an ideal hiding spot for fish.

Matt Wilhelm explains how to fish undercut banks with terrestrials.

Mastering the art of casting near these underwater hideaways is crucial. Perfecting a reach cast, an upstream maneuver designed to ensure a natural drift, can enhance the fly’s allure, making it almost irresistible to the hiding fish. This presentation mimics terrestrials’ natural fall into the water, a common occurrence that predatory fish are finely attuned to. Properly executed, this technique increases the chances of a successful catch, combining skill with understanding the fish’s behavior and habitat.

Key Takeaways

  • Terrestrial fly fishing targets fish using imitations of land-based insects cast near undercut banks.
  • The reach cast technique allows for a natural, drag-free fly presentation, increasing the likelihood of enticing fish.
  • Undercut banks serve as prime feeding locations where fish actively watch for falling terrestrials.

Essential Techniques for Fishing Terrestrials

Artificial flies that mimic land insects can be highly effective. Anglers often target areas where fish seek refuge and are likely to encounter natural prey, such as grasshoppers, ants, crickets, and beetles.

The “undercut bank” is a strategic location formed when the current carves out space beneath the bank’s edge. These areas range from a modest recess to more pronounced cavities extending several feet. Undercut banks offer fish shelter from overhead threats and a vantage point for feeding.

One beneficial technique when casting to an undercut bank is the “reach cast.” This involves casting the line upstream and to the side—left in this instance—to allow the artificial lure to drift naturally past the bank. By adjusting the cast, the line mends upstream, helping to maintain a natural float past the secluded area where fish might be waiting. While a strike may not always occur on the first attempt, the undercut bank provides a promising opportunity for a successful catch due to the likely presence of fish.

Comprehending Streambank Erosion

Explaining Undercut Banks

An undercut bank, often found in flowing water systems, is formed where the water’s motion has washed away soil beneath the edge, creating a space extending several feet. These recesses are notable for their overhanging edges, which shelter aquatic life.

The Significance of Undercut Banks for Aquatic Life

Eroded river edges are crucial habitats for fish, especially as they offer protection and prime feeding grounds. In these hidden spots, fish can safely ambush food, such as land insects that may fall into the water, making these areas especially favorable for catching fish using terrestrial imitations.

Showcasing Fly Fishing Skills

Pick the Right Fly

Before you begin, ensure you have the right fly—imitations of grasshoppers, ants, crickets, or beetles are optimal. It’s critical to identify a promising fishing spot such as an undercut bank—a stream edge that’s eroded below, creating a shelter for fish. An effective spot could extend a couple of feet or much more beneath the bank, providing both safety and a prime feeding ground for fish.

  • Select the Proper Fly: Grasshopper imitation
  • Identify Fishing Location: Undercut bank

Conducting the Reach Cast

The reach cast technique involves casting your line upstream and to one side—left in this case—to better position the fly. This method allows the fly to drift naturally beside the bank, enhancing the chances of attracting a fish.

  • Casting Direction: Upstream and to the left
  • Objective: Natural placement beside the undercut bank

Line Mending

After casting, it is essential to mend your line to manage its flow with the current. Mending the line means lifting and moving it on the water to eliminate unwanted drag, allowing the fly to drift uninterruptedly to entice a fish.

  • Action: Lift and adjust the line post-cast
  • Goal: Eliminate drag for uninterrupted drift

A Natural Drift Is the Best

The fly’s ultimate goal is to achieve a drag-free float. The fly should move with the current to mimic a real terrestrial insect and increase the chances of a fish strike.

  • Desired Result: Drag-free float
  • Technique Benefit: Maximizes the chance of a fish strike

Strategy and Technique Refinement

Practice makes perfect. Do not give up even if the initial attempts do not yield success. Persistence in casting is key. The goal is a nice drag-free drift as close to the undercut bank as possible. Do that, and eventually, the fish will respond!