St. Vrain Creek (often known locally as the
St. Vrain River) is a tributary of the
South Platte RiverThe South Platte River, historically known as the Rio Jesus Maria, is one of the two principal tributaries of the Platte River and itself a major river of the American West, located in the U.S. states of Colorado and Nebraska...
, approximately 40 miles (64 km) long, in north central
ColoradoColorado is a U.S. state located in the Rocky Mountain region of the United States of America. It may also be considered to be part of the Western and Southwestern regions of the United States. Colorado entered statehood in 1876 and was nicknamed the “Centennial State”...
in the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
. It drains part of the foothills north of
BoulderBoulder is a Home Rule Municipality that is the county seat and most populous city of Boulder County, Colorado, in the United States. Boulder is the 11th most populous city in the state of Colorado. The United States Census Bureau estimates that in 2008 the population of the city of Boulder was...
and the
Colorado PiedmontThe Colorado Piedmont is the geologic term for an area along the base of the foothills of the Front Range in north central Colorado in the United States...
area in the vicinity of
LongmontLongmont is a Home Rule Municipality in Boulder and Weld counties in the U.S. state of Colorado. Longmont is the 13th most populous city in the State of Colorado. The word "Longmont" comes from Longs Peak, a prominent mountain named for explorer Stephen H. Long that is clearly visible from...
.
The creek is formed by the confluence of North and South St. Vrain creeks at
LyonsLyons is a Statutory Town in Boulder County, Colorado, United States. The population was 1,585 at the 2000 census. Lyons is located at the confluence of the North St. Vrain Creek and the South St. Vrain Creek, twenty miles east of Rocky Mountain National Park. Due to its location at the...
. The creek rises in several branches in the foothills of the
Front RangeThe Front Range is a mountain range of the Rocky Mountains of North America that is located in the north-central portion of the U.S. State of Colorado...
northwest of Boulder.
St. Vrain Creek (often known locally as the
St. Vrain River) is a tributary of the
South Platte RiverThe South Platte River, historically known as the Rio Jesus Maria, is one of the two principal tributaries of the Platte River and itself a major river of the American West, located in the U.S. states of Colorado and Nebraska...
, approximately 40 miles (64 km) long, in north central
ColoradoColorado is a U.S. state located in the Rocky Mountain region of the United States of America. It may also be considered to be part of the Western and Southwestern regions of the United States. Colorado entered statehood in 1876 and was nicknamed the “Centennial State”...
in the
United StatesThe United States of America is a federal constitutional republic comprising fifty states and a federal district...
. It drains part of the foothills north of
BoulderBoulder is a Home Rule Municipality that is the county seat and most populous city of Boulder County, Colorado, in the United States. Boulder is the 11th most populous city in the state of Colorado. The United States Census Bureau estimates that in 2008 the population of the city of Boulder was...
and the
Colorado PiedmontThe Colorado Piedmont is the geologic term for an area along the base of the foothills of the Front Range in north central Colorado in the United States...
area in the vicinity of
LongmontLongmont is a Home Rule Municipality in Boulder and Weld counties in the U.S. state of Colorado. Longmont is the 13th most populous city in the State of Colorado. The word "Longmont" comes from Longs Peak, a prominent mountain named for explorer Stephen H. Long that is clearly visible from...
.
The creek is formed by the confluence of North and South St. Vrain creeks at
LyonsLyons is a Statutory Town in Boulder County, Colorado, United States. The population was 1,585 at the 2000 census. Lyons is located at the confluence of the North St. Vrain Creek and the South St. Vrain Creek, twenty miles east of Rocky Mountain National Park. Due to its location at the...
. The creek rises in several branches in the foothills of the
Front RangeThe Front Range is a mountain range of the Rocky Mountains of North America that is located in the north-central portion of the U.S. State of Colorado...
northwest of Boulder. Middle St. Vrain Creek rises along the
continental divideA continental divide is a drainage divide on a continent such that the drainage basin on one side of the divide feeds into one ocean or sea, and the basin on the other side either feeds into a different ocean or sea, or else is endorheic, not connected to the open sea...
, west of St. Vrain Mountain. It descends in canyon to flow along
State Highway 7State Highway 7 in the U.S. state of Colorado is a state highway. Approximately long, it is located in the north-central portion of the state, traversing the mountains on the east of the continental divide south of Estes Park as well as portions of the Colorado Piedmont north of Denver...
and past Raymond. It joins the shorter South St. Vrain Creek just below Raymond. North St. Vrain Creek rises northeast of St. Vrain Mountain near
AllensparkAllenspark is a census-designated place in Boulder County, Colorado, United States. The population was 496 at the 2000 census. The Allenspark Post Office has the ZIP Code 80510.-Geography:Allenspark is located at ....
and descends in a canyon to the east along U.S. Highway 36. The two branches join at
LyonsLyons is a Statutory Town in Boulder County, Colorado, United States. The population was 1,585 at the 2000 census. Lyons is located at the confluence of the North St. Vrain Creek and the South St. Vrain Creek, twenty miles east of Rocky Mountain National Park. Due to its location at the...
, at the mouth of the canyon. East of Lyons, the combined stream flows southeast through farmland and ranch country, passing south of
HygieneHygiene is an unincorporated community with a U.S. Post Office in Boulder County, Colorado, United States. The Hygiene Post Office has the ZIP Code 80533. This community's name stems from a time when it had a sanitarium to work with tuberculosis patients. The sanitarium was started in 1882 Jacob S...
and entering Longmont. It passes through the south side of Longmont where it is rimmed by a greenway trail and several parks. East of Longmont it flows generally northeast, meandering through a wide river bottom in ranch country and passing under Interstate 25 south of the intersection with
State Highway 66Colorado State Highway 66 is a long state highway in Larimer,Boulder, and Weld counties in Colorado. The highway is concurrent with the larger route, US 36 from Estes Park to Lyons. SH 66 passes through the foothills of the Rocky Mountains proceeding east to Longmont where it passes US 287. It...
. It joins the South Platte from the west just upstream from the ruins of
Fort St. VrainFort Saint Vrain was an 19th century fur trading post located at the confluence of Saint Vrain Creek and the South Platte River about 20 miles east of the Rocky Mountains in the unorganized territory of the United States that would later become the State of Colorado. A historical marker notes the...
and approximately 4 miles (6.4 m) northwest of
PlattevillePlatteville is a Statutory Town in Weld County, Colorado, United States. The population was 2,370 at the 2000 census. It is adjacent to Fort Vasquez on US Highway 85.-Geography:Platteville is located at ....
.
The creek rivers Left Hand Creek south of Longmont and
Boulder CreekBoulder Creek is a creek draining the Rocky Mountains to the west of Boulder, Colorado, as well as the city itself and surrounding plains.- Route :...
east of Longmont.