The Mountain Home AFB plate. Relief from Copernicus GLO-30; rivers and lakes from USGS NHD; watersheds from the USGS Watershed Boundary Dataset; roads and city limits from Census TIGER 2024.
Mountain Home AFB’s center stands about 2,990 ft above sea level. Within three miles the land runs from 2,970 ft to 3,080 ft, a difference of 110 ft: gently rolling country. The highest named summit within 15 miles is Lockman Butte, about 3,770 ft, 13 miles north-northeast.
Under the town center the state geologic map shows Basalt (Pleistocene and Pliocene), from the Late Pliocene to Pleistocene, less than 3 million years old.
The section below crosses 3 rock units mapped at the surface.
Heights every 0.1 mile from the Copernicus GLO-90 surface model; vertical exaggeration about 18×. The colored band under the surface is the rock the state geologic map shows at the surface, not a picture of what lies beneath.
Basalt. Age: Late Pliocene to Pleistocene, less than 3 million years old. About 17 mi of the line.
Mixed-clastic, volcanic. Age: Early Miocene to Pleistocene, 2 to 16 million years old. About 6 mi of the line.
Fine-detrital. Age: Quaternary, less than 2.6 million years old. About 1 mi of the line.
From the USGS State Geologic Map Compilation (Horton and others, 2017), the states’ geologic maps joined at a common scale.
Heights from Copernicus GLO-90 (a surface model: it includes buildings and tree canopy); summits from USGS GNIS; rivers from USGS NHDPlus HR; rock from the USGS State Geologic Map Compilation.
A raindrop that lands in Mountain Home AFB reaches the Pacific Ocean by way of Canyon Creek, the Snake and the Columbia: about 820 river miles.
Lakes on the way: Lake Umatilla, Brownlee Reservoir, Cove Arm Lake and Hells Canyon Reservoir.
240 miles of the trip are on the Snake.
Traced down the USGS NHDPlus V2.1 river network from the Census center point of Mountain Home AFB; river miles along the main stem, rounded.