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What We Do

What We Do

BK-Riverfish was established in 2008 to develop a fish ladder for the 21st Century that passes riverine fish at dams and culverts, and to provide consulting services involving behavior and conservation of sturgeons and diverse migratory riverine fish.

See how our fish ladder works! Watch a continuous stream of fish resting in our ladder’s protective eddies then completing their natural migrations through our ladder to the top of the Stockdale Dam.

We’ve developed the ONLY fish ladder in North America that passes a diverse riverine fish community.

Click here to see data on the fish species that are passing upstream using our prototype ladder!


Our unique stainless - steel Kynard Alternating Side Baffle Fish Ladder KASBL (Patent-Pending) passes riverine fish with a moderate swimming ability that range from 1.5 inches up to 32 inches long.

Our Patent-Pending* technology is the result of many years of research and development to create a modular ladder that’s portable and easily assembled on-site.

  • Our 2-foot-wide ladder (Patent-Pending) passes fish up to 2-feet-long over dams and through culverts.
  • Our 1-foot-wide ladder (Patent-Pending) passes fish up to 1-feet-long over dams and through culverts.
  • Our 3-foot-wide ladder (Patent Pending) passes fish from 3 to 32 inches long and is ideal for moderate-size streams.
  • Standard height is 2-feet, but can be higher on any model.
Finished Ladder at Stockdale Dam on Eel River, IN

* Provisional Patent #62/433,762

BK Riverfish, LLC.


  • Survey of your dam site and river
  • Design of ladder specific to your site
  • Fabrication of ladder
  • Transport of ladder to dam site
  • Assembly and installation assistance
  • Consulting with local civil engineers
  • Assisting with permits
  • Video evaluation of fish passage

We will work with you to bring our technology to your dam or culvert!

Our Prototype Fish Ladder is successfully passing thousands of fish at Stockdale Dam on the Eel River in Indiana!

In a partnership with Manchester University and the US Fish & Wildlife Service, BK-Riverfish’s modular 11 section, two-foot-wide by two-foot-high, 73-foot long steel Patent-Pending* Kynard Alternating Side Baffle Ladder (KASBL) was installed at Stockdale Dam in August 2017.

* Provisional Patent #62/433,762.


Quick Facts about Our Prototype Ladder on the Eel River:

  • More than 60,000 fish ranging between 1.5 inches up to 22 inches-long swam to the top of our ladder from May through November 2018.
  • 42 species ascended our Patent-Pending KASBL – that’s 81% of the 52 species in that stretch of the Eel River! This shows that most of these fish are migratory.
  • Five of six species of Darters ascended our ladder. Other identified species using our ladder are Rock Bass and several species of Shiners.
  • Assembly of our 73-foot ladder took just 10 hours.
  • Installation was completed within one and a half weeks.
  • Total cost of the ladder at Stockdale Mill Dam was about $125,000 (costs vary for each project depending on factors like size, site work & services needed).
  • Our ladder encased in concrete and with grill cover sustained no damage from severe winter floods (8 feet over the ladder) and debris was cleared within 30 minutes.
  • Our ladder allows fish to also move downstream without injury.

The research on performance of our ladder comes from graduate student Cassi Root, Central Michigan University, and indicates that most U.S. riverine species need to migrate upstream (just like fish in England and Europe). The large number of fish using our ladder in the Eel River likely plays a major role in the productivity and ecology of the fish community upstream of the dam.

Our ladder is now connecting these migratory fish populations, which for more than 100 years have been divided into upstream and downstream populations.

We are currently developing a new ladder design for Sturgeons. Contact us to learn more!

Ladder on truck en route

Here is our just-fabricated ladder on a truck en route to a new site


We have a combined 72 years of experience in fish behavior research with work throughout the United States and in Australia, Europe, China and Brazil.

Since 2008, BK-Riverfish has provided consulting services involving behavior and conservation of sturgeons and diverse migratory riverine fish for clients including Sierra Club, U.S. Army Corps of Engineers and Southern Environmental Law Center.

Our services include field and artificial stream research
on-site and in our laboratory.

Dr. Kynard’s research is the foundation for conservation projects throughout the world, like the Yangtze River Estuary Chinese Sturgeon Nature Preserve in China:


BK Riverfish, LLC.

Our Hydraulic Fish Behavior Research Laboratory is located in an historic mill in Erving, Massachusetts. It is a fully equipped lab with seven artificial stream tanks, an experimental flume, video to record behavior and a reliable water supply.

At lab
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