This dataset contains polygons representing deposits of hyaloclastic debris that were generated between about 3.5 and 3.0 million years ago when a series of basaltic lava flows entered the canyon of the ancestral Columbia River. The lava flows were erupted from volcanoes in the area of the Hood River graben of McClaughry and others (2012), generally have low-potassium tholeiitic basalt composition, and were part of a widespread pulse of mafic volcanism in the northern Oregon Cascade Range that occurred between about 4.4 and 2.1 million years ago (Conrey and others, 1996). Lava flows that entered the ancestral Columbia River were rapidly chilled and fragmented during interaction with water (Trimble, 1963, Swanson, 1986; McClaughry and others, 2012). The voluminous hyaloclastic debris was swept downstream and accumulated as thick deposits in the eastern Portland Basin (Swanson, 1986). The canyon that the ancestral Columbia River occupied, known as the Bridal Veil channel (Tolan, 1982; Tolan and Beeson, 1984), was eventually filled by the hyaloclastite and related lava flows and the river was diverted to the north, where it has carved its present canyon. Argon–argon (40Ar/39Ar) age determinations for lava flows interbedded with and overlying the hyaloclastite (McClaughry and others, 2012; Fleck and others, 2014) suggest the hyaloclastite was deposited between about 3.5 and 3.0 million years ago. The hyaloclastic deposits (map unit Ttfh) are equivalent to the Troutdale Formation upper member of Tolan and Beeson (1984) and include the Troutdale Formation hyaloclastic sandstone member of Evarts (2006), Evarts and O'Connor (2008), Evarts, O'Connor, and Tolan (2013), and Wells and others (2020). Although the hyaloclastic deposits are generally sandstones in the western Columbia Gorge and Portland Basin, they contain pillow lavas and basaltic breccia in the area between Hood River, Oregon and Bonneville Dam. Most clasts in the hyaloclastic deposits are olivine-phyric basalt that is rich in basaltic glass (sideromelane) that is commonly altered to yellow-brown colored palagonite. At some localities in the western Columbia Gorge, the hyaloclastic deposits include beds of micaceous quartzose sandstone. This dataset also includes polygons representing the partial extents of lava flows (map unit Tlkt) that are either interbedded with or overlie the hyaloclastic deposits. The lava flows generally have tholeiitic basalt composition with low levels of potassium (less than 0.5 weight percent K2O), commonly contain olivine phenocrysts, and often have a diktytaxitic groundmass texture consisting of numerous small angular voids. The lava flows are equivalent to the late Pliocene lavas of the late High Cascades grouping of McClaughry and others (2012). It should be noted that there are numerous lava flows of similar age and composition in the region but this dataset mostly contains those that can be used to constrain the history of the hyaloclastic deposits in the Bridal Veil channel. This data release is a compilation that includes incomplete geologic mapping and it is anticipated that extents of these deposits will be expanded in future geologic maps. The source maps upon which most of this dataset was derived from were intended for use at 1:24,000 scale. References Cited: Conrey, R.M., Sherrod, D.R., Uto, K., and Uchiumi, S., 1996, Potassium-argon ages from Mount Hood area of Cascade Range, northern Oregon: Isochron/West, no. 63, p. 10-20. Evarts, R.C., 2006, Geologic map of the Lacamas Creek quadrangle, Clark County, Washington, U.S. Geological Survey Scientific Investigations Map 2924, scale 1:24,000, https://doi.org/10.3133/sim2924. Evarts, R.C., and O'Connor, J.E., 2008, Geologic map of the Camas Quadrangle, Clark County, Washington, and Multnomah County, Oregon, U.S. Geological Survey Scientific Investigations Map 3017, scale 1:24,000, https://doi.org/10.3133/sim3017. Evarts, R.C., O'Connor, J.E., and Tolan, T.L., 2013, Geologic map of the Washougal quadrangle, Clark County, Washington, and Multnomah County, Oregon, U. S. Geological Survey Scientific Investigations Map 3257, scale 1:24,000, https://doi.org/10.3133/sim3257. Fleck, R.J., Hagstrum, J.T., Calvert, A.T., Evarts, R.C., and Conrey, R.M., 2014, 40Ar/39Ar geochronology, paleomagnetism, and evolution of the Boring volcanic field, Oregon and Washington, USA: Geosphere, v. 10, no. 6, p. 1283-1314, https://doi.org/10.1130/ges00985.1. McClaughry, J.D., Wiley, T.J., Conrey, R.M., Jones, C.B., and Lite, K.E., 2012, Digital geologic map of the Hood River Valley, Hood River and Wasco Counties, Oregon: Open-File Report O-12-03, 130 p., https://www.oregongeology.org/pubs/ofr/p-O-12-03.htm. Swanson, R.D., 1986, A stratigraphic-geochemical study of the Troutdale Formation and Sandy River Mudstone in the Portland basin and lower Columbia River Gorge, Portland State University, M.S. thesis, 115 p, https://doi.org/10.15760/etd.5604. Tolan, T.L., 1982, The stratigraphic relationships of the Columbia River Basalt Group in the lower Columbia River Gorge of Oregon and Washington, Portland State University, M.S. thesis, 169 p, https://doi.org/10.15760/etd.3232. Tolan, T.L., and Beeson, M.H., 1984, Intracanyon flows of the Columbia River Basalt Group in the lower Columbia River Gorge and their relationship to the Troutdale Formation: GSA Bulletin, v. 95, no. 4, p. 463-477, https://doi.org/10.1130/0016-7606(1984)95%3C463:IFOTCR%3E2.0.CO;2. Trimble, D.E., 1963, Geology of Portland, Oregon, and adjacent areas: U. S. Geological Survey Bulletin 1119, https://doi.org/10.3133/b1119. Wells, R.E., Haugerud, R.A., Niem, A.R., Niem, W.A., Ma, L., Evarts, R.C., O'Connor, J.E., Madin, I.P., Sherrod, D.R., Beeson, M.H., Tolan, T.L., Wheeler, K.L., Hanson, W.B., and Sawlan, M.G., 2020, Geologic map of the greater Portland metropolitan area and surrounding region, Oregon and Washington: U.S. Geological Survey Scientific Investigations Map 3443, scale 1:63,360, https://doi.org/10.3133/sim3443.

This polygon coverage depicts historical vegetation in the Willamette Valley, Oregon, including portions of Clark County, Washington along the Columbia River. It is based on land survey data recorded by General Land Office (GLO) surveyors between 1851 and 1910, including township and section line data. It was completed in stages, funded by the Oregon Department of State Lands (1995, 1996), the USDI Bureau of Land Management (1995, 1997, 1999), the Oregon Community Foundation (1997), the Environmental Protection Agency (1997), the City of Portland Bureau of Environmental Services (1997), the Oregon Department of Fish and Wildlife (2000), the USDA Forest Service (2002, 2008), The Nature Conservancy (2007), and Metro (2007). Date of last data update: 1910 This is official RLIS data. Contact Person: Joe Gordon joe.gordon@oregonmetro.gov 503-797-1587 RLIS Metadata Viewer: https://gis.oregonmetro.gov/rlis-metadata/#/details/2202 RLIS Terms of Use: https://rlisdiscovery.oregonmetro.gov/pages/terms-of-use

Estuarine ecosystems are controlled by a variety of processes that operate at multiple spatial and temporal scales. Understanding the hierarchical nature of these processes will aid in prioritization of restoration efforts. This hierarchical Columbia River Estuary Ecosystem Classification (henceforth "Classification") of the Columbia River estuary is a spatial database of the tidally-influenced reaches of the lower Columbia River, the tidally affected parts of its tributaries, and the landforms that make up their floodplains for the 230 kilometers between the Pacific Ocean and Bonneville Dam. This work is a collaborative effort between University of Washington School of Aquatic and Fishery Sciences (henceforth "UW"), U.S. Geological Survey (henceforth "USGS"), and the Lower Columbia Estuary Partnership (henceforth "EP"). Consideration of geomorphologic processes will improve the understanding of controlling physical factors that drive ecosystem evolution along the tidal Columbia River.

The Classification is organized around six hierarchical levels, progressing from the coarsest, regional scale to the finest, localized scale: (1) Ecosystem Province; (2) Ecoregion; (3) Hydrogeomorphic Reach; (4) Ecosystem Complex; (5) Geomorphic Catena; and (6) Primary Cover Class. For Levels 4 and 5, we mapped landforms within the Holocene floodplain primarily by visual interpretation of Light Detection and Ranging (LiDAR) topography supplemented with aerial photographs, Natural Resources Conservation Service (NRCS) soils data, and historical maps. Mapped landforms are classified as to their current geomorphic function, the inferred process regime that formed them, and anthropogenic modification. Channels were classified primarily by a set of depth-based rules and geometric relationships. Classification Level 5 floodplain landforms ("geomorphic catenae") were further classified based on multivariate analysis of land-cover within the mapped landform area and attributed as "sub-catena".

The extent of detailed mapping is the interpreted Holocene geologic floodplain of the tidal Columbia River and its tributaries to the estimated head of tide. The extent of this dataset also includes tributary valleys that are not mapped in detail. The upstream extents of tributary valleys are an estimation of the limit of Columbia River influence and are for use as containers in future analyses. The geologic floodplain is the geomorphic surface that is actively accumulating sediment through occasional overbank deposition. Most features within the geologic floodplain are considered to be formed during the recent (Holocene-epoch) climatic regime. There are bedrock and pre-Holocene sedimentary deposits included where they are surrounded by Holocene sediment accumulations or have been shaped by Holocene floods. In some places, Holocene landforms such as landslides, tributary fans, and coastal dunes are mapped that extend outside of the modern floodplain.

This map is not a floodplain hazard map or delineation of actual flood boundaries. Although wetlands are included in the Classification, they are based on different criteria than jurisdictional wetlands. The extent of mapping may differ from the actual limit of tidal influence.