About Us

Our Mission

To reduce the human-caused spread of invasive species by promoting behavior change.


Robert Wiltshire | Executive Director

Robert Wiltshire founded the Invasive Species Action Network in 2008 realizing that the current efforts to address the aquatic invasive species problem fell short. With a well-rounded career conducting wild trout studies for the state of Montana for over 15 years, small-business entrepreneur in recreation and hobbies, and conservation non-profit manager for more than a decade, Bob navigates his current role as director with ease.

He has played key roles in the management of invasive species over the years including serving on the Montana’s Whirling Disease Task Force, co-authoring the Western States New Zealand Mud Snail Management plan and currently serving on the National Invasive Species Advisory Committee to the White House.

Leah Elwell | Program Director

Leah Elwell joined ISAN in 2010 as seasoned hand in invasive species issues and research. Many years of river ecology research created a desire to protect our water resources from invasives. She holds a graduate degree in Biology which focused on complex interactions of whirling disease host species.

Elwell has provided a variety of publications as author on ecology and management of whirling disease and didymo. She has been featured in an educational film on whirling disease research. When not dreaming up new ways to change the world for good, Leah is digging in the dirt, hiking the hills and having fun with her family.

Matt Wilhelm | Education Director

Matt Wilhelm joined ISAN in 2009 with over 12 years of experience reaching out to youth on aquatic education. Matt specializes in teaching concepts about river ecology, aquatic invertebrates, native fish species, aquatic and weed invaders, and fly angling education.

Wilhelm has been a contract provider of aquatic education needs in schools across Montana for the last 12 years and has worked with over 30,000 people over the years. He is a nationally recognized instructor who has been teaching teachers about fly fishing and in 2004 he was honored with the Montana American Fisheries Society Aquatic Educator of the Year Award.

Wilhelm has been featured as an educator on local, regional and national TV programming, including ESPN. Matt is also owner of the Yellowstone Fly Fishing School and holds a FFF Master Fly Casting Instructor Certification. When Matt is not teaching, then you will find him wading or floating the river.

Marya Spoja | Fishing and Boating Program Coordinator

Our newest member of the team, Marya, brings with her a decade of experience in the fishing industry. By spending her summers as a fishing guide and in fishing retail, and her winters as a dogsledding guide, her career has long revolved around water in its various forms. Through these experiences Marya has seen first-hand the relationship between water and her local economy, a complex relationship that over time fostered in her a desire to do more for those who enjoy spending time on the water.

When she isn’t guiding or working on our various outreach programs, Marya beats the door down to spend some more time outside.