Ten Mile River (California)

Ten Mile River (California)
Ten Mile Creek, Tenmile
stream
Ten Mile River, looking north from California 1
Country	United States
State	California
Region	Mendocino
Tributaries
- left	Middle Fork Ten Mile Creek, Mill Creek, California, South Fork Ten Mile Creek
- right	North Fork Ten Mile Creek
Source	Confluence of North Fork Ten Mile Creek and Middle Fork Ten Mile Creek
- elevation	49 ft (15 m)
- coordinates	39°33′10″N 123°46′01″W / 39.55278°N 123.76694°W / 39.55278; -123.76694
Mouth	Pacific Ocean
- elevation	0 ft (0 m)
- coordinates	39°33′10″N 123°46′01″W / 39.55278°N 123.76694°W / 39.55278; -123.76694Coordinates: 39°33′10″N 123°46′01″W / 39.55278°N 123.76694°W / 39.55278; -123.76694

Ten Mile River is a river in northern Mendocino County, California, United States. It is named for the fact that its mouth is 10 miles (16 km) north of the mouth of the Noyo River. The middle and north forks of the river are each 15 miles (24 km) long, and the river extends for seven more miles from their confluence to its mouth, on the Pacific Ocean. The watershed of Ten Mile River is neighbored on the south by the Noyo River and on the east and north by the South Fork Eel River. 75 acres (30 ha) of salt marsh provide a habitat for many birds. Ten Mile Beach, in MacKerricher State Park, extends approximately five miles southward from the mouth of the river to Cleone, including approximately 1,300 acres (530 ha) of what has been called California's "most pristine stretch of sand dunes."

The Ten Mile River basin has been logged continuously since the early 1870s. At first, trees were cut using single-bladed axes and dragged by oxen to mills at Fort Bragg, ten miles to the south. Railroad lines were introduced on the South Fork in 1910 and on the other parts of the river in the 1920s. In the 1930s, the railroads were replaced by tractor roads; after the passage of the California Forest Practice Act in 1973, tractor logging on steeper slopes was supplanted by more environmentally friendly practices such as the use of cables. The timber on both sides of the river was logged by the Georgia Pacific Company until 1999, when Georgia-Pacific's holdings in the area were acquired by the Hawthorne Timber Company. Timber in the area is logged on a 60-year rotation.

An 1861 story in Harper's Monthly includes a passage recounting the crossing of Ten Mile River: "We found the crossing a little dangerous on account of the tide, which sometimes renders it impassable for several hours, except by swimming. With some plunging, spurring, and kicking, the opposite side was gained in due time". Later, the river was spanned near its mouth by a bridge on California State Route 1, north of the community of Inglenook. A concrete beam bridge replaced an older wooden deck truss bridge in 1954. After studies found that the 1954 bridge was insufficiently earthquake-safe, a new concrete box girder bridge on Highway 1 was constructed in 2009. The new bridge is 45 feet (14 m) wide and 1,479 feet (451 m) long; it cost $43.5 million to construct.