The Mattole River's mainstem is 62 miles (100 km) in length and has more than 74 tributaries.
 It has historically had large runs of salmon and steelhead trout, but due to past logging, road building and severe floods in 1955 and 1964, all of which impacted the river, fish numbers have declined.
The coho salmon is a federally listed threatened species (Southern Oregon/Northern California populations) that use the Mattole River  and its tributary, Mill Creek.
Increased sediment and lack of tree cover reduced the quality and quantity of fish habitat by increasing summer water temperatures.
The Environmental Protection Agency added the Mattole River to the state's list of impaired watersheds in 1992.

The Mattole Estuary is where the waters of the land meet and mix with the tidewaters of the Pacific Ocean, and acts as a settling basin for both river sediment and sand from ocean waves, and will eventually fill to become a meadow.
The Bureau of Land Management designated the Mattole Estuary as an "Area of Critical Environmental Concern" in 1981.
 This area, now at more than 650 acres (2.6 km²), has significant cultural, historic, wildlife and habitat resources.

The watershed, or catchbasin of the river has been seriously impacted from past road building, and restoration efforts include abandonment of some roadways as well as reshaping and upgrading of others.

Other fish species in the Mattole River include the Pacific lamprey, threespine sickleback, and the starry flounder.

The historic Punta Gorda Lighthouse located near the estuary of the Mattole River.
The Mattole River's mainstem is 62 miles (100 km) in length and has more than 74 tributaries.  It has historically had large runs of salmon and steelhead trout, but due to past logging, road building and severe floods in 1955 and 1964, all of which impacted the river, fish numbers have declined. The coho salmon is a federally listed threatened species (Southern Oregon/Northern California populations) that use the Mattole River  and its tributary, Mill Creek. Increased sediment and lack of tree cover reduced the quality and quantity of fish habitat by increasing summer water temperatures. The Environmental Protection Agency added the Mattole River to the state's list of impaired watersheds in 1992.
The Mattole Estuary is where the waters of the land meet and mix with the tidewaters of the Pacific Ocean, and acts as a settling basin for both river sediment and sand from ocean waves, and will eventually fill to become a meadow. The Bureau of Land Management designated the Mattole Estuary as an "Area of Critical Environmental Concern" in 1981.  This area, now at more than 650 acres (2.6 km²), has significant cultural, historic, wildlife and habitat resources.
The watershed, or catchbasin of the river has been seriously impacted from past road building, and restoration efforts include abandonment of some roadways as well as reshaping and upgrading of others. 
Other fish species in the Mattole River include the Pacific lamprey, threespine sickleback, and the starry flounder.
The historic Punta Gorda Lighthouse located near the estuary of the Mattole River.
King Range Wilderness