NPS Geodiversity Atlas—Whitman Mission National Historic Site, Washington

Geodiversity refers to the full variety of natural geologic (rocks, minerals, sediments, fossils, landforms, and physical processes) and soil resources and processes that occur in the park. A product of the Geologic Resources Inventory, the NPS Geodiversity Atlas delivers information in support of education, Geoconservation, and integrated management of living (biotic) and non-living (abiotic) components of the ecosystem.

image of whitman mission gri report cover with landscape photo
In-depth geologic information is contained in the baseline inventory products of the Geologic Resources Inventory, see table below.


Whitman Mission National Historic Site is located west of the Blue Mountains near the confluence of the Walla Walla River and Mill Creek in Walla Walla County, Washington. Originally established as Whitman National Monument on June 29, 1936, the park unit was redesignated as a national historic site on January 1, 1963 (National Park Service 2016a). The 56-hectare (139 acre) site is the location of the 1836 American Board of Commissioners for Foreign Missions (ABCFM) Christian mission established by Marcus and Narcissa Whitman. Ignorance, racism, and ethnocentrism associated with the ABCFM towards the Weyíiletpuu (Cayuse) and Walúulapam (Walla Walla) tribes resulted in many deaths and served as a catalyst for the expansion of the United States into the Pacific Northwest (National Park Service 2016a). WHMI preserves a sacred piece of Cayuse homeland, interpreting the tragic events surrounding the 19th-century Christian mission, memorializing those who died there and promoting a deeper understanding of its lasting impact on history (National Park Service 2017). Located on a steep hill surrounded by the floodplain of the Walla Walla River and Mill Creek, WHMI contains a restored mill pond and creek, an apple orchard, and historic buildings such as the Mission House site, blacksmith shop, and grist mill.

Geologic Setting

Situated in the Columbia Basin physiographic province, Whitman Mission National Historic Site and its immediate surroundings overlie the buried remnants of one of the largest continental flood basalt eruptions to occur in the Western Hemisphere. Approximately 17–6 million years ago, lava flows of the Columbia River Basalt Group erupted across the region of Idaho, Oregon, and Washington and flooded about 160,000 km2 (63,000 mi2 ) of the Columbia Plateau (Graham 2014b). During the Pleistocene, cataclysmic flooding associated with failures of glacially dammed lakes transformed the WHMI region as floodwaters accumulated behind Wallula Gap. When floodwaters abruptly slowed at Wallula Gap, sediments settled out of suspension in the quiet waters beginning with coarser, heavier gravel and sand grains followed by finer-grained silt and clay. At least 40 times the repeated formation and failure of glacially dammed lakes produced a cycle of sedimentation that are recorded in Pleistocene rhythmites (Touchet Beds) located in WHMI (Graham 2014b).

Regional Geology

Whitman Mission is a part of the Columbia Plateau Physiographic Province and shares its geologic history and some characteristic geologic formations with a region that extends well beyond park boundaries.

Maps and Reports

image of whitman mission gri geologic map

The Geologic Resources Inventory produces digital geologic maps and reports for more than 270 natural resource parks. The products listed below are currently available for this park, check back often for updates as many maps, reports, and posters are still in progress.
  • Scoping summaries are records of scoping meetings where NPS staff and local geologists determined the park’s geologic mapping plan and what content should be included in the report.
  • Digital geologic maps include files for viewing in GIS software, a guide to using the data, and a document with ancillary map information. Newer products also include data viewable in Google Earth and online map services.
  • Reports use the maps to discuss the park’s setting and significance, notable geologic features and processes, geologic resource management issues, and geologic history.
  • Posters are a static view of the GIS data in PDF format. Newer posters include aerial imagery or shaded relief and other park information. They are also included with the reports.
  • Projects list basic information about the program and all products available for a park.

Source: Data Store Saved Search 3198. To search for additional information, visit the Data Store.

NPS Soil Resources Inventory project has been completed for Whitman Mission National Historic Site and can be found on the NPS Data Store.

Source: Data Store Saved Search 3223. To search for additional information, visit the Data Store.

Related Articles

Whitman Mission National Historic Site

National Park Service Geodiversity Atlas

The servicewide Geodiversity Atlas provides information on geoheritage and geodiversity resources and values within the National Park System. This information supports science-based geoconservation and interpretation in the NPS, as well as STEM education in schools, museums, and field camps. The NPS Geologic Resources Division and many parks work with National and International geoconservation communities to ensure that NPS abiotic resources are managed using the highest standards and best practices available.

Whitman Mission National Historic Site

Last updated: July 18, 2024