Techniques

Reading Water: A Guide to Finding Trout

By Lia BarskeyOctober 7, 20255 min read
Back to Blog
Share this post:

The Art and Science of Reading Water

The ability to read water – to look at a river and identify where trout are likely holding – separates successful anglers from those who simply cast randomly and hope for the best. This fundamental skill allows you to fish efficiently, targeting high-probability areas rather than covering unproductive water.

Understanding Trout Behavior

Before you can read water effectively, you need to understand what trout need to survive and thrive:

  • Food – A steady supply of aquatic insects and other prey
  • Shelter – Protection from predators and strong currents
  • Oxygen – Well-oxygenated water, typically found in riffles and runs
  • Comfortable temperature – Between 50-65°F for optimal activity

The best fishing spots provide all four of these elements in close proximity, allowing trout to feed actively while expending minimal energy.

Prime Holding Water

Riffles and Runs

Riffles are shallow, fast-moving sections where water breaks over rocks, creating a choppy surface. These areas are oxygen-rich and produce abundant aquatic insects, making them prime feeding zones. Look for the transition zones where riffles flow into deeper runs – these spots often hold the largest fish.

Pools

Deeper pools serve as resting and holding areas, especially during midday or when fish aren't actively feeding. Focus on:

  • Pool heads – Where faster water enters the pool
  • Pool tails – The shallow exit where food funnels through
  • Deep slots – The deepest part of the pool, often along cutbanks

Pocket Water

Pocket water consists of small pools and cushions formed around boulders and rocks in faster currents. Each pocket can hold one or more fish taking advantage of the current break while intercepting food swept past their position.

"I always tell my clients: don't just look at the water's surface. The real story is happening underneath. Where's the current breaking? Where's the food funneling? That's where you'll find fish." – Lia Barskey

Reading Current Seams

Current seams – the visible lines where fast and slow water meet – are among the most productive fishing spots. Trout position themselves in the slower water, making short feeding forays into the faster current where food is concentrated.

How to Fish Seams

  • Cast into the faster water and let your fly drift along the seam
  • Use upstream mending to achieve a drag-free drift
  • Work from the downstream end upward to avoid spooked fish
  • Pay attention to where seams converge – these are prime holding spots

Structure and Cover

Anything that breaks the current or provides overhead cover can hold trout:

Natural Features

  • Large boulders – Create current breaks and feeding lanes
  • Logjams – Provide excellent cover and food production
  • Undercut banks – Offer protection and shade
  • Overhanging vegetation – Provides terrestrial insects and cover

Substrate Considerations

The river bottom tells you a lot about fish habitat:

  • Gravel and cobble – Excellent for insect production and spawning
  • Boulder fields – Create complex holding water
  • Bedrock ledges – Form depth changes and current breaks
  • Silt or sand – Generally less productive, but check edges

Seasonal Water Reading

Spring (Runoff)

During high water, trout seek refuge from strong currents. Focus on:

  • Eddies and slower side channels
  • Bank edges where current is reduced
  • Areas behind large obstacles

Summer (Low, Clear Water)

Fish become more selective and seek cooler, well-oxygenated water:

  • Deeper pools and runs
  • Shaded areas under overhanging trees
  • Spring seeps and tributary mouths
  • Riffles and pocket water for feeding

Fall

As water temperatures drop, fish become more aggressive:

  • Main current seams and runs
  • Tailouts of pools where food concentrates
  • Deeper holes as spawning approaches

Visual Cues on the Water

Surface Indicators

Learn to spot these visual clues:

  • Rises – Concentric rings indicating feeding fish
  • Foam lines – Mark current seams and food lanes
  • Color changes – Indicate depth variations
  • Bubbles – Collect in eddies where fish often hold

The Systematic Approach

When approaching new water, follow this process:

  1. Observe from a distance – Identify likely holding water before wading
  2. Start downstream – Work your way up to avoid spooking fish
  3. Fish close water first – Many anglers overlook productive water near the bank
  4. Cover water efficiently – Focus on high-probability zones
  5. Adjust based on results – If a spot produces, fish similar water

Practice and Patience

Reading water is a skill that develops over time and experience. Each river has unique characteristics, and conditions change daily. The more time you spend observing water and noting where you find fish, the better your water-reading skills become.

Tips for Improvement

  • Study water when you're not fishing – observe fish behavior from bridges
  • Keep a fishing journal noting successful spots and conditions
  • Pay attention to where other anglers find success
  • Consider hiring a guide to learn local water-reading techniques

Mastering the art of reading water transforms your fishing experience. Instead of covering miles of river randomly, you'll develop the ability to walk up to any stream, identify the best holding water, and consistently find fish. This skill is transferable to any river system and will serve you throughout your fly fishing journey.

Ready to Experience Colorado's Best Fishing?

Book a guided trip with Lia and discover the techniques and waters that will transform your fly fishing experience.