The late Wisconsin Icicle Creek alpine glacier transported tonalite boulders from the Mount Stuart batholith to arcuate end moraines in Icicle valley and Wenatchee valley near Leavenworth. Some previous workers considered sparsely weathered Mount Stuart boulders lying outside these moraines and draped by silt as having been ice rafted in a late Wisconsin lake. But the boulders are more likely within drift or end moraines of pre-late Wisconsin glaciations correlative to lateral moraines on Boundary Butte. The silt—a younger deposit that covers the boulders—derives not from a physically ponded lake but apparently from brief Missoula flood(s) backflooding up the valley.

The Pleistocene Missoula floods through eastern and central Washington are by peak fl ow rate (discharge) the greatest freshwater cataclysms known on Earth. Newly explored features along the Wenatchee reach of Columbia valley give new evidence and revise earlier interpretations of size, frequency, and routing of megafloods.

Crystalline-rock erratics derived far northeast lie scattered about the sandstone hills of lower Wenatchee valley and adjacent Columbia valley up to 495 m altitude, 320 m above Columbia River. They can only have been ice-rafted by flood(s) running down the Columbia. Before the late Wisconsin Okanogan lobe of Cordilleran ice blocked the Columbia, at least one monstrous Missoula flood poured down the valley past Wenatchee and backflooded Wenatchee valley.

Rhythmically bedded sandy silt in Columbia valley between Trinidad and Wenatchee records repeated silt-rich backfloods up the Columbia from Quincy basin—after Okanogan-lobe ice had blocked the Columbia upvalley. Rhythmically graded silt beds in Wenatchee valley at Dryden containing Columbia-derived dropstones record ten Missoula backfloods up the valley.

Thick silt farther up Wenatchee valley between Peshastin and Leavenworth had been thought deposits of a long-lived lake, dammed supposedly by the Malaga landslide. But the heights and distribution of provable lake beds now make Moses Coulee bar the only viable dam—and only up to altitude 275 m. The silt above Dryden lying at 315–385 m altitude must also have been laid by Missoula floods.

During the last seventy years, numerous models have been developed to predict soil erosion; some models also predict concomitant sediment deposition. All have been proven inadequate and/or inaccurate in one respect or another. This paper discusses the application of the new-generation Unit Stream Power Erosion and Deposition (USPED) model at the US Army's Yakima Training Center (YTC), Washington. We incorporated a novel approach that compares model results with observed soil erosion and sediment deposition across the landscape in a spatially distributed fashion. The model results matched visually estimated values 90% of the time, providing an encouraging validation of the model. Historically, erosion models have been compared with sediment outflow from watersheds, providing no information regarding sources and sinks of erosion and deposition within watersheds. The USPED model is relatively simple to apply and the validation approach provides information in terms of the intensity and spatial distribution of soil erosion and sediment deposition that can be used to optimize the placement and size of soil erosion and sediment control efforts.

Located in the Pacific Northwest, the Columbia River basin provides important spawning and rearing habitat for Pacific salmon and steelhead (Oncorhynchus spp.). These species were historically abundant throughout the basin but have experienced extensive declines linked to a complex suite of factors. These declines, in tandem with their cultural and economic significance, have led Pacific salmon and steelhead to become one of the most intensely managed groups of species in North America. Management actions have increasingly recognized the importance of genetic resources and have expanded the use of genetic tools to provide powerful data for the conservation and management of Pacific salmon. We provide a summary of historic management actions in the basin with a focus on those relevant to genetic applications. We describe the initial recognition of genetic differences and distinction of population units, how genetics applies to the hatchery controversy, as well as the progression of genetic investigations and applications used in management. Further, we outline some emerging and potential future genetic tools.

Biodiversity in aquatic ecosystems is generally viewed as a reliable indicator of ecosystem health. High biodiversity indicates a healthy ecosystem that functions properly because of the right combination of physical, chemical, and biological factors. Anthropogenic disturbance decreases biodiversity by modifying these factors. The Grande Ronde and Imnaha River basins in northeastern Oregon are occupied by land uses that could be disturbing aquatic ecosystems. Biological assessments (bioassessments) were used in this study to determine the effects of disturbance on macroinvertebrate community structure within the Grande Ronde, Wallowa, and Imnaha rivers. Macroinvertebrate distribution and abundance data collected from upstream and downstream sites on each river were used to calculate species- and community-level metrics (e.g., richness, abundance and the Family Biotic Index [FBI]) for each site. These metrics revealed differences between sites and between rivers, as well as a decrease in water quality and biodiversity for the Grande Ronde and Imnaha rivers. The Wallowa River did not conform to this trend, likely because the upstream site was directly below an oligotrophic lake. In general, metrics were not indicative of impaired macroinvertebrate communities, but management efforts should be taken to conserve biodiversity in lower reaches of rivers within the Grande Ronde and Imnaha river basins.

Once common throughout surface waters west of the Rocky Mountains, the western ridged mussel (Gonidea angulata Lea) has been extirpated throughout much of its range (Blevins et al. 2017). This species is currently listed as endangered in Canada (COSEWIC 2010), where its northernmost occurrences are thought to be in Okanagan Lake within the southern interior of British Columbia. Recovery plans are legally required for listed species; but for G. angulata, recovery planning is a challenge as little is known about its habitat requirements, particularly within lakes. To be able to recover G. angulata throughout its historic range, we must study lentic as well as lotic habitats. We developed habitat suitability models for G. angulata in Okanagan Lake using snorkel survey data, habitat data, and two complementary classification methods based on the RandomForest algorithm. Both classification methods ranked the top four predictor variables as effective fetch between 1 and 2.25 km, medium-high embeddedness of substrates (25 to > 75%), high proportion of sand in the substrate, and low slope (0–20%). In comparison, G. angulata habitat in river systems have been described as having low sediment accumulation, boulders that offer refuge, low flow variability, and bank stability. These findings suggest that the drivers for G. angulata distribution in lakes are similar to those in rivers, although predictor variables themselves may vary. This is important because simply using predictor variables from lotic systems would not correctly predict G. angulata occurrence in lakes, demonstrating the importance of this lake-specific investigation.

We estimated the age of inscriptions on a rock outcrop by estimating the ages of lichens that had overgrown the inscriptions. The inscriptions are considered to be historically important, potentially representing some of the earliest European exploration of Neahkahnie Mountain, the highest point along the Pacific coast from Baja California to Strait of Juan de Fuca, Washington. The rock bearing the inscriptions was destroyed by road construction activities in about 1970–1980, but the inscriptions had been photographed with sufficient detail to allow diameter estimates for the lichens on the rock, affording an opportunity for dating based on lichen sizes. Aspicilia and Placopsis are currently the only lichen genera that are common on similar outcrops in the area and form large light-colored discrete individuals with a radial form. We therefore derived a calibration curve for lichen size in relation to age based on Aspicilia and Placopsis sizes on nearby surfaces of known age (road cuts and stone walls), then applied that curve to the diameters of lichens in the photo. Based on the sizes of the lichens on the rock outcrop with inscriptions, the rock face had been available for lichen colonization and growth for > 100 yrs and perhaps shows a pulse of recruitment following extensive wildfires on the immediate coast in the 1840s. Calculated lichen ages are within 25 years of the expected time of US Army exploration of Neahkahnie Mountain under Captain C. C. Augur in the mid-1800s.