The Potlatch River is a smaller little known river that flows into the Clearwater River about 15 miles upstream of Lewiston, Idaho. For those familiar with this river, images of raging dirty water in the spring and barely a trickle in the summer often come to mind. At first appearance, this is hardly a river that one would consider to support any type of a quality fishery. Years of habitat degradation from farming, logging, grazing and human development has taken its toll on this river. However, about 10 years ago the Idaho Department of Fish and Game began surveying this river and what we learned was truly a surprise.
This river supported a thriving population of truly wild steelhead with almost no hatchery influence. Upon talking to some of the locals, they told stories of when their grandfathers caught steelhead in tributaries that are now dry. It became evident that this river had a lot of potential to produce more steelhead, and that is when it was decided to embark on a major habitat restoration program in this basin. To help direct where money is spent, we initiated a monitoring program to better understand where the steelhead occur, how many there are, and how they respond to the various habitat improvement projects.
We are currently in our tenth field season of studying the steelhead population in the Potlatch River basin. Much of our monitoring occurs in the East Fork Potlatch River and Big Bear Creek, two of the major steelhead producing drainages in the Potlatch. Our monitoring program consists of three major components. We trap adult steelhead at a weir to estimate how many spawn. We use two rotary screw traps (see picture to the right) to catch juvenile steelhead to evaluate the number of smolts that migrate to the ocean each year. And we use PIT tag arrays to learn when adult and juvenile fish implanted with a small microchip enter or leave certain streams. By using at all this data, we can assess steelhead survival and how well the habitat restoration program is working.
Adult steelhead travel over 500 miles from the Pacific Ocean to spawn in tributaries of the Potlatch River. Since 2008, we have estimated between 71-106 adult steelhead return annually to the East Fork Potlatch River to spawn. In 2014, we estimated 96 adults returned to the East Fork which is the 3rd highest return to date. In one of the strong run years, we believe around 1,000 adult steelhead entered the Potlatch River to spawn somewhere in the watershed.
Juvenile steelhead leave the Potlatch River tributaries typically from March-June as they begin their journey to the Pacific Ocean. We monitor this outmigration and estimate the number of juveniles departing from Big Bear Creek and the East Fork Potlatch River drainages. In 2014, we estimated approximately 8,356 juvenile steelhead out-migrated from the Big Bear Creek drainage and 11,126 from the East Fork Potlatch River drainage. These estimates are typical and have ranged from 7,000-48,000 in the East Fork and 4,000-20,000 in Big Bear Creek. The picture below shows our crew PIT tagging juvenile steelhead.
We will continue to monitor and evaluate the steelhead population in the Potlatch watershed as habitat restoration efforts continue. The IDFG, Latah Soil and Water Conservation District, Natural Resource Conservation Service, US Forest Service, and Nez Perce Tribe have made significant efforts to improve habitat in this watershed. These efforts help insure this steelhead population will thrive for years to come and ultimately provide new fishing opportunities for anglers. - Jason Fortier, Senior Fish Technician, Clearwater Region