Distribution and Current Status
 In North America, steelhead are found in Pacific Ocean drainages from southern California through Alaska. In Asia, they are found on the east and west coast of the Kamchatka Peninsula, with a few populations on the mainland. In the state of California, known populations occur in coastal rivers and streams from Malibu Creek in Los Angeles County up to the Smith River near the Oregon border, and in the Sacramento River system.
Historically, large runs of steelhead trout made their way up the Napa River to spawn in its tributaries. The local steelhead population has been greatly reduced. The National Marine Fisheries Service (now called NOAA Fisheries) listed steelhead as a threatened species in Napa County in August 1997. However, adult steelhead are still observed spawning in many of the Napa River's tributaries on a yearly basis, and juvenile steelhead can be seen in the summer months. The Napa River watershed is still considered one of the most significant anadromous fish streams within San Francisco Bay.
In California, steelhead were once abundant in coastal and Central Valley rivers and streams. A rough estimate of the total statewide steelhead population is 250,000 adults. This is less than half the population of 30 years ago. The major factor causing steelhead population decline is freshwater habitat loss and degradation. This has resulted from three main factors: inadequate stream flows, blocked access to historic spawning and rearing areas due to dams, and human activities that discharge sediment and debris into waterways.
Source: Steelhead Restoration and Management Plan for California, by Dennis McEwan and Terry Jackson, CA Department of Fish and Game, and
The Napa Watershed Owner's Manual, Napa County RCD |
