The Mowich River is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in the U.S. state

U.S. state

A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

 of Washington. Its watershed

Drainage basin

A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...

 drains a portion of the western side of Mount Rainier

Mount Rainier

Mount Rainier is a massive stratovolcano located southeast of Seattle in the state of Washington, United States. It is the most topographically prominent mountain in the contiguous United States and the Cascade Volcanic Arc, with a summit elevation of . Mt. Rainier is considered one of the most...

, part of the Cascade Range

Cascade Range

The Cascade Range is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, and the notable volcanoes known as the High Cascades...

. The river has two main headwater

Source (river or stream)

The source or headwaters of a river or stream is the place from which the water in the river or stream originates.-Definition:There is no universally agreed upon definition for determining a stream's source...

 branches, the South Mowich River and the North Mowich River. The South Mowich is significantly larger and sometimes considered the main river. The Mowich and its tributaries drain several of Mount Rainier's glaciers. The upper portion of its watershed is contained within Mount Rainier National Park

Mount Rainier National Park

Mount Rainier National Park is a United States National Park located in southeast Pierce County and northeast Lewis County in Washington state. It was one of the US's earliest National Parks, having been established on March 2, 1899 as the fifth national park in the United States. The park contains...

. The river flows into the Puyallup River

Puyallup River

The Puyallup River is a river in the U.S. state of Washington. About long, it is formed by glaciers on the west side of Mount Rainier. It flows generally northwest, emptying into Commencement Bay, part of Puget Sound...

 in the foothills west of Mount Rainier.

The name "Mowich" come from the Chinook Jargon

Chinook Jargon

Chinook Jargon originated as a pidgin trade language of the Pacific Northwest, and spread during the 19th century from the lower Columbia River, first to other areas in modern Oregon and Washington, then British Columbia and as far as Alaska, sometimes taking on characteristics of a creole language...

 word for "deer". Originally used for Mowich Lake

Mowich Lake

Mowich Lake is a lake located in the northwestern corner of Mount Rainier National Park in Washington State at an elevation of . The name "Mowich" derives from the Chinook jargon word for deer....

, the name was later applied to the river and the glacier.

Sources

Meltwater from Mount Rainier's Edmunds Glacier

Edmunds Glacier

The Edmunds Glacier is a medium-sized glacier on Mount Rainier in Washington. Named in 1883 for Vermont George F. Edmunds, who visited nearby Spray Park that year, the body of ice covers 0.5 mile2 and has a volume of 1.1 billion feet3 . The glacier lies on the western flank of the volcano below...

, South Mowich Glacier

South Mowich Glacier

The South Mowich Glacier is a glacier located on the western flank of Mount Rainier in Washington. It covers and contains 4.5 billion ft3 of ice. Starting from the high-altitude cliffs above the Sunset Amphitheater at over , the glacier flows west down Mount Rainier. The glacier is connected to...

, and North Mowich Glacier

North Mowich Glacier

The North Mowich Glacier is a glacier located on the northwest flank of Mount Rainier in Washington. It covers and contains 9.5 billion ft3 of ice. Starting from the foot of Rainier's steep Mowich Face at about , the glacier first consists of two lobes of ice that flow downhill to the northwest....

 feed the north and south branches of the Mowich River. Other rivers originate in glacier

Glacier

A glacier is a large persistent body of ice that forms where the accumulation of snow exceeds its ablation over many years, often centuries. At least 0.1 km² in area and 50 m thick, but often much larger, a glacier slowly deforms and flows due to stresses induced by its weight...

s just south and north of the Mowich River's glaciers. To the south, the Puyallup Glacier

Puyallup Glacier

The Puyallup Glacier is a glacier on the west flank of Mount Rainier in Washington. It covers and contains 10.2 billion ft3 of ice. Sharing the same source of ice as the northern South Mowich Glacier, the Puyallup Glacier begins as a branch off the ice stream that flow out of the Sunset...

 gives rise to the Puyallup River, while to the north the Carbon Glacier

Carbon Glacier

Carbon Glacier is an album by Laura Veirs, released in 2004. The song Rapture was heard during the episode "Save Me", from the first season of Grey's Anatomy.-Track listing:#"Ether Sings" – 3:44#"Icebound Stream" – 3:04#"Rapture" – 3:06...

 creates the Carbon River

Carbon River

The Carbon River is a river in the U.S. state of Washington. It flows about 30 miles from its source, the Carbon Glacier on Mount Rainier, to join the Puyallup River at Orting....

.

South Mowich River

The South Mowich River's headwater tributaries flow around a highland called Jeanette Heights. The river, having been formed by meltwater from the South Mowich and Edmunds Glacier, flows northwest for several miles. Several (all unnamed) glacier-fed streams gather into the South Mowich River on its way to its confluence with the North Mowich. The two join just inside the western boundary of Mount Rainier National Park.

Another highland, the plateau-like Sunset Park lies just southwest of the South Mowich River. The Wonderland Trail

Wonderland Trail

The Wonderland Trail is an approximately 93 mile hiking trail that circumnavigates Mount Rainier in Mount Rainier National Park, Washington, United States. The trail goes over many ridges of Mount Rainier for a cumulative of elevation gain. The trail was built in 1915...

 passes through Sunset Park and descends into the valley of the South Mowich River, crossing it just above the confluence of the south and north branches. The Wonderland Trail then crosses the North Mowich River and climbs to Mowich Lake and another highland area called Spray Park.

North Mowich River

The North Mowich River's headwater tributaries drain North Mowich Glacier near an area of Mount Rainier called Division Rook. Shortly below the toe of the glacier, the river drops over a large wall, forming Moraine Falls, the first of two waterfalls on the river, both of which are very difficult to access and would take several days to reach on foot. Giant Falls, just as difficult to reach, is located a ways downstream of Moraine Falls. Ptarmigan Ridge separates the North Mowich River's headwaters from Spray Park, much of which is drained by other tributaries of the North Mowich River. Spray Creek rises in Spray Park, tumbles over Spray Falls, and collects a tributary called Grant Creek. Spray Creek then flows down from Spray Park and along the bottom of the steep slope called Eagle Cliff, after which it joins the river.

Shortly below the Spray Creek confluence, the North Mowich River is joined by Crater Creek, which flows from Mowich Lake a few miles to the north. Various tributary creeks, many of which drain Spray Park, flow into Crater Creek. The North and South Mowich Rivers then join just downstream.

Mowich River Proper

After the North Mowich and South Mowich join to form the Mowich River Proper which flows west. It passes Paul Peak to the north, then exits Mount Rainier National Park. Just outside the park the river is joined by Meadow Creek. Then the Mowich River flows by Martin Peak to the north before curving southwest and flowing through a broad, glacier-carved valley. Rushingwater Creek joins the Mowich River just before the Mowich River itself joins the Puyallup River.

Tributaries

South Mowich River

No major tributaries

North Mowich River

• Spray Creek
• Crater Creek

Mowich River Proper

• Meadow Creek
• Rushingwater Creek

Geology

Formed by glacial meltwater, the Mowich River contains a heavy load of sediment

Sediment

Sediment is naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of fluids such as wind, water, or ice, and/or by the force of gravity acting on the particle itself....

 such as silt and gravel. After descending from the upper slopes of Mount Rainier the Mowich River flows through a broad glacier-carved valley where thick sediment deposits in the stream bed

Stream bed

A stream bed is the channel bottom of a stream, river or creek; the physical confine of the normal water flow. The lateral confines or channel margins, during all but flood stage, are known as the stream banks or river banks. In fact, a flood occurs when a stream overflows its banks and flows onto...

 create sand and gravel bars causing the river to become complexly braided

Braided river

A braided river is one of a number of channel types and has a channel that consists of a network of small channels separated by small and often temporary islands called braid bars or, in British usage, aits or eyots. Braided streams occur in rivers with high slope and/or large sediment load...

 and meander

Meander

A meander in general is a bend in a sinuous watercourse. A meander is formed when the moving water in a stream erodes the outer banks and widens its valley. A stream of any volume may assume a meandering course, alternately eroding sediments from the outside of a bend and depositing them on the...

ing.

As with other rivers sourced high on Mount Rainier, the Mowich River valley, as well as the Puyallup into which the Mowich flows, are at risk of lahar

Lahar

A lahar is a type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris, and water. The material flows down from a volcano, typically along a river valley. The term is a shortened version of "berlahar" which originated in the Javanese language of...

s.