The Willapa Hills is a

geologic Geology () is a branch of natural science concerned with Earth and other astronomical objects, the features or rocks of which it is composed, and the processes by which they change over time. Modern geology significantly overlaps all other Eart ...

physiographic Physical geography (also known as physiography) is one of the three main branches of geography. Physical geography is the branch of natural science which deals with the processes and patterns in the natural environment such as the atmosphere, ...

, and

geographic Geography (from Greek: , ''geographia''. Combination of Greek words ‘Geo’ (The Earth) and ‘Graphien’ (to describe), literally "earth description") is a field of science devoted to the study of the lands, features, inhabitants, and ...

region in southwest Washington. When described as a physiographical province, the Willapa Hills are bounded by the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

to the west, the

Columbia River The Columbia River (Upper Chinook: ' or '; Sahaptin: ''Nch’i-Wàna'' or ''Nchi wana''; Sinixt dialect'' '') is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, C ...

to the south, the

Olympic Mountains The Olympic Mountains are a mountain range on the Olympic Peninsula of the Pacific Northwest of the United States. The mountains, part of the Pacific Coast Ranges, are not especially high – Mount Olympus is the highest at ; however, the easter ...

to the north, and the

Cascade Range The Cascade Range or Cascades 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, ...

to the east. Some definitions place the Puget Lowland physiographic province east of the Willapa Hills. Included within the province are the

Black Hills The Black Hills ( lkt, Ȟe Sápa; chy, Moʼȯhta-voʼhonáaeva; hid, awaxaawi shiibisha) is an isolated mountain range rising from the Great Plains of North America in western South Dakota and extending into Wyoming, United States. Black Elk P ...

, the Doty Hills, and a number of broad river valleys, some of which open up into broad

estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environment ...

on the Pacific such as

Grays Harbor Grays Harbor is an estuary, estuarine bay located north of the mouth of the Columbia River, on the southwest Pacific coast of Washington (U.S. state), Washington state, in the United States of America. It is a ria, which formed at the end of the l ...

and

Willapa Bay Willapa Bay () is a bay located on the southwest Pacific coast of Washington state in the United States. The Long Beach Peninsula separates Willapa Bay from the greater expanse of the Pacific Ocean. With over of surface area Willapa Bay is the ...

. Other definitions do not include the Black Hills. The

USGS The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, a ...

GNIS The Geographic Names Information System (GNIS) is a database of name and locative information about more than two million physical and cultural features throughout the United States and its territories, Antarctica, and the associated states of ...

defines the Willapa Hills as bounded by the Columbia River to the south and the Chehalis River to the north, without giving specific east and west bounds. The Willapa Hills are one of the

Pacific Coast Ranges The Pacific Coast Ranges (officially gazetted as the Pacific Mountain System in the United States) are the series of mountain ranges that stretch along the West Coast of North America from Alaska south to Northern and Central Mexico. Although the ...

, which continue north as the Olympic Mountains and south, across the Columbia River, as the

Oregon Coast Range The Oregon Coast Range, often called simply the Coast Range and sometimes the Pacific Coast Range, is a mountain range, in the Pacific Coast Ranges physiographic region, in the U.S. state of Oregon along the Pacific Ocean. This north-south runni ...

. The highest point is Boistfort Peak. The Willapa Hills are the lowest uplands in the entire Pacific Coast Range system. Almost all of the land is privately held and has been repeatedly logged. Only a few

long corners Long may refer to: Measurement * Long, characteristic of something of great duration * Long, characteristic of something of great length * Longitude (abbreviation: long.), a geographic coordinate * Longa (music), note value in early music mens ...

remain with virgin forest.

Alder Alders are trees comprising the genus ''Alnus'' in the birch family Betulaceae. The genus comprises about 35 species of monoecious trees and shrubs, a few reaching a large size, distributed throughout the north temperate zone with a few sp ...

s less than twenty years old are typically harvested for

pulp mill A pulp mill is a manufacturing facility that converts wood chips or other plant fiber sources into a thick fiber board which can be shipped to a paper mill for further processing. Pulp can be manufactured using mechanical, semi-chemical, or ful ...

s. The Willapa Hills receive abundant rainfall and a number of rivers originate in the region, including the Chehalis River,

Willapa River The Willapa River is a river on the Pacific coast of southwestern Washington in the United States, approximately long. It drains an area of low hills and a coastal plain into Willapa Bay, a large estuary north of the mouth of the Columbia River. ...

, North River,

Bone River The Bone River is a short river in the U.S. state of Washington (state), Washington. It is about long.Calculated in Google Earth Course The Bone River originates in the hills of the southwestern part of Washington, close to the source of the Pal ...

Niawiakum River The Niawiakum River is a short river in the U.S. state of Washington. It is approximately long.Calculated in Google Earth Course The Niawiakum River originates in the hills of the southwestern part of Washington. It flows generally west, empt ...

, Palix River, Bear River,

Naselle River The Naselle River is a river in the U.S. state of Washington. Course The Naselle River originates in the Willapa Hills and flows generally west, passing the community of Naselle before emptying into the southern part of Willapa Bay. Tributaries ...

, Grays River, and Elochoman River, among others.

Notes

{{Authority control Hills of Washington (state) Landforms of Pacific County, Washington Physiographic provinces Mountains of Lewis County, Washington