Mill Creek is a large

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a stream ...

northern California Northern California (colloquially known as NorCal) is a geographic and cultural region that generally comprises the northern portion of the U.S. state of California. Spanning the state's northernmost 48 counties, its main population centers incl ...

. It is an eastside tributary of the

Sacramento River The Sacramento River ( es, Río Sacramento) is the principal river of Northern California in the United States and is the largest river in California. Rising in the Klamath Mountains, the river flows south for before reaching the Sacramento–S ...

, draining an area of and flowing for .U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data
The National Map
, accessed March 10, 2011 The creek begins in

Shasta County, California Shasta County (), officially the County of Shasta, is a county in the northern portion of the U.S. state of California. Its population is 182,155 as of the 2020 census, up from 177,223 from the 2010 census. The county seat is Redding. Shasta ...

, but almost immediately flows into

Tehama County, California Tehama County ( ; Wintun for "high water") is a county located in the northern part of the U.S. state of California. As of the 2020 census, the population was 65,829. The county seat and largest city is Red Bluff. Tehama County comprises the ...

. The creek's source is a

thermal spring A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circ ...

at an elevation of in

Lassen Volcanic National Park Lassen Volcanic National Park is an American national park in northeastern California. The dominant feature of the park is Lassen Peak, the largest plug dome volcano in the world and the southernmost volcano in the Cascade Range. Lassen Vol ...

. At first, the creek flows roughly south while meandering to the east and west, but the lower two-thirds of the creek flow roughly southwest until it reaches the Sacramento River at an elevation of only , just north of

Los Molinos, California Los Molinos (Spanish for "The Mills") is a census-designated place (CDP) in Tehama County, California, United States. The population was 2,037 at the 2010 census, up from 1,952 at the 2000 census. History Los Molinos ("the mills" in Spanish) tra ...

. In the creek's upper reaches, it flows through

meadows A meadow ( ) is an open habitat, or field, vegetated by grasses, herbs, and other non-woody plants. Trees or shrubs may sparsely populate meadows, as long as these areas maintain an open character. Meadows may be naturally occurring or artificia ...

and dense

forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...

s. Later, it descends through a steep

canyon A canyon (from ; archaic British English spelling: ''cañon''), or gorge, is a deep cleft between escarpments or cliffs resulting from weathering and the erosion, erosive activity of a river over geologic time scales. Rivers have a natural tenden ...

and flows into the Sacramento Valley. It flows about in the

valley A valley is an elongated low area often running between Hill, hills or Mountain, mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers ...

before it reaches its confluence with the Sacramento River. The creek is in excellent condition, due to the upper two-thirds of it being in the protected lands of

and

Lassen National Forest Lassen National Forest is a United States national forest of 1,700 square miles (4,300 km2) in northeastern California. It is named after pioneer Peter Lassen, who mined, ranched and promoted the area to emigrant parties in the 1850s. Wildl ...

. There are no storage

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use ...

s or

reservoirs A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including control ...

on the creek, but there are several diversion dams after it reaches the Sacramento Valley. The creek is home to Spring Run Chinook Salmon and Central Valley Steelhead (both endangered), Fall Run Chinook Salmon, and Pacific Lamprey. Mill Creek received its name in the 1840s by an explorer who proposed

watermill A watermill or water mill is a mill that uses hydropower. It is a structure that uses a water wheel or water turbine to drive a mechanical process such as milling (grinding), rolling, or hammering. Such processes are needed in the production of ...

s be built along its course. Mill Creek is primarily in private ownership. Many of the property owners participate in the Mill Creek Conservancy, a 501C 3 non-profit corporation formed in 1994 by local landowners, local community, and others committed to the continued protection and management of Mill Creek’s historically pristine ecosystem by promoting resource protection and compatible land usage through cooperative efforts between landowners, federal and state agencies and other stakeholders. Partners include th
Los Molinos Mutual Water CompanyCalifornia’s Department of Fish & Wildlife
the U.S. Fish & Wildlife Service, the

Nature Conservancy The Nature Conservancy (TNC) is a global environmental organization headquartered in Arlington, Virginia. it works via affiliates or branches in 79 countries and territories, as well as across every state in the US. Founded in 1951, The Natu ...

, and many other agencies and conservation organizations to create ongoing programs that protect and enhance the survival of Mill Creek’s threatened and endangered Chinook salmon and steelhead populations.

Notes

References

California Department of Water ResourcesKlamath Resource Information System
(PDF)
Friends of the RiverMill Creek Conservancy
{{coord missing, Shasta County, California Rivers of Shasta County, California Rivers of Tehama County, California Tributaries of the Sacramento River Rivers of Northern California