North Subbasin Overview
The Northern Subbasin is located between the Estuary Subbasin and Honeydew Creek at River Mile 26.5 (RM 26.5) along the northeastern side of the Mattole mainstem. Eighteen perennial streams drain a watershed area of 98 square miles. Elevations range from five feet at the estuary to approximately 2,500 feet in the headwaters of the tributaries.
The Northern Subbasin is largely managed for timber production and cattle ranching. The town of Petrolia is located in this subbasin at the confluence of the North Fork Mattole River and the Mattole River. The subbasin overall is very rural with some back-to-land homesteads located near Petrolia and other residential areas within the subbasin.
Historically, the Northern Subbasin supported runs of Chinook and coho salmon and steelhead trout; however, the subbasin appears to be the most impacted of the Mattole subbasins due to naturally occurring geologic processes and land use. The subbasin is most likely limited primarilyto runs of steelhead trout as sightings of Chinook salmon are limited and coho salmon have not been observed in recent decades.