Trinity County is a large, rugged and mountainous, heavily forested county located in the northwestern portion of the U.S. state of California, along the Trinity River and within the Salmon/Klamath Mountains.
Its county seat and largest town is Weaverville, at around 3500 people. There are no incorporated cities in Trinity County. The county has a total area of 3,208 mi², 99% of it is land and 1% of it is water. The county hosts many visitors during summer months, for camping, backpacking, and fishing. As of 2000, there were 13,022 people residing in the county.