View of the Cascade Rapids on the Columbia River, taken from the Oregon side of the Columbia River Gorge. Upper Block House, also known as Fort Lugenbeel, is visible in the background on the left.

View of the Upper Block House, also known as Fort Lugenbeel, on the Columbia River in the Columbia River Gorge. Other buildings and a railroad bridge are also visible. OHS Collection includes 2 duplicates of this mammoth plate on different mounts. One duplicate bears Watkins' signature on the back and has the alternate title, "Upper Blockhouse, Cascades."

View of the Columbia River Gorge from the Upper Block House, also known as Fort Lugenbeel, in the Washington Territory. View looks down the Columbia River. Railroad tracks border the river.

A steam locomotive operated by the Oregon Steam and Navigation Company on railroad tracks in the Washington Territory of the Columbia River Gorge. Upper Block House, also known as Fort Lugenbeel, is on the left while a steamboat on the Columbia River is visible in the distance on the right.

View looking southwest down the Columbia River from the Middle Block House, also known as Fort Rains, in the Washington Territory. The Eagle Creek area is visible in the distance on the Oregon side of the river.

View of the Middle Block House, also known as Fort Rains, on the Columbia River. OHS Collection includes 1 duplicate of this mammoth plate on a different mount.

View of the former garrison at Fort Cascades, near the Cascades townsite on the Columbia River in Skamania County, Washington Territory, 1867. Castle Rock, also known as Beacon Rock, is visible in the distance.

Distant view of Castle Rock, also known as Beacon Rock, across the Columbia River on the Washington side of the Columbia River Gorge. Taken from the McCrary farm in Oregon. OHS Collection includes 1 duplicate of this mammoth plate on a different mount.

View of Castle Rock, also known as Beacon Rock, on the Washington side of the Columbia River Gorge. OHS Collection includes 2 duplicates of this mammoth plate on different mounts.

View of Cape Horn on the Washington side of the Columbia River Gorge. Taken from the east at John Stevenson’s property. Log cabin and fence in the foreground. OHS Collection includes 1 duplicate of this mammoth plate on a different mount, with the alternate title, "Cape Horn On Columbia River."

View of Cape Horn on the Washington side of the Columbia River Gorge, looking up the Columbia River. OHS Collection includes 1 duplicate of this mammoth plate on a different mount, with the alternate title, "Cape Horn Below the Cascades."

Left panel of Carleton Watkins' 3-part panorama of Portland, Or., 1867. Mount St. Helens is in the background. Duplicate of Mammoth 402, on a different mount.

Left panel of Carleton Watkins' 3-part panorama of Portland, Or., 1867. Mount St. Helens is in the background. Duplicate of Mammoth 402, on a different mount.

Left panel of Carleton Watkins' 3-part panorama of Portland, Or., 1867. Mount St. Helens is in the background. Duplicate of Mammoth 402, on a different mount.

Left panel of Carleton Watkins' 3-part panorama of Portland, Or., 1867. Mount St. Helens is in the background.

View of Cape Horn across the river on the Washington side of the Columbia River Gorge, taken from Bridal Veil, Oregon during the winter storm of 1884-1885. This plate is part of an album of Watkin’s New Series photographs originally owned by Charles H. Prescott, manager of the Oregon Railroad and Navigation Co.

View of Castle Rock, also known as Beacon Rock, on the Washington side of the Columbia River Gorge. Photo taken from up river on the Oregon side of the gorge. Railroad tracks in the foreground.

View of Castle Rock, also known as Beacon Rock, on the Washington side of the Columbia River Gorge. Photo taken from the Oregon side of the gorge. There are 2 structures, possibly houses, on the shore of the Columbia River.

Winter view of Cape Horn on the Columbia River, taken from Bridal Veil on the Oregon side of the Columbia River Gorge. Patches of snow and some small waterfalls on the cliffs of Cape Horn.

The Cascades rapids of the Columbia River. The blockhouse at Fort Cascades is in the background. Loose duplicate plate in 7/1. This plate is part of Carlton Watkin's "Sun Sketches of Columbia River Scenery" album.

View of Castle Rock, also known as Beacon Rock, on the Washington side of the Columbia River Gorge. Photo taken from the Oregon side of the Columbia River Gorge. There are 2 structures, possibly houses, on the shore of the Columbia River. This plate is part of Carlton Watkin's "Sun Sketches of Columbia River Scenery" album.

View of Cape Horn on the Washington side of the Columbia River Gorge, looking down the Columbia River. There is a fence and large tree stump in the foreground. Loose duplicate plate in 5/1. This plate is part of Carlton Watkin's "Sun Sketches of Columbia River Scenery" album.

View of Cape Horn on the Washington side of the Columbia River Gorge, looking up the Columbia River. Loose, cropped duplicate plate in 5/1. This plate is part of Carlton Watkin's "Sun Sketches of Columbia River Scenery" album.

Boudoir card of Castle Rock (also known as Beacon Rock) across the Columbia River on the Washington side of the Columbia River Gorge. Photo taken from Oregon side of the Gorge. There is a railroad in the foreground.

Boudoir card of Castle Rock (also known as Beacon Rock) across the Columbia River on the Washington side of the Columbia River Gorge. Photo taken from Oregon side of the Gorge. There is a railroad in the foreground.

Photograph of 2 groups of men facing each other at a railroad construction site on the Washington side of the Columbia River Gorge. The men on the left stand around a railroad track under construction and watch as a construction worker clears the land. The men on the right appear to be construction workers, and they look up at the other group. Homesteads are visible in the background. Handwritten note on the back of the print reads, "Troubles between the P. & S. and C. Valley men at Carson, Wash." Second note reads, "Near Monaghan Homestead. Return to Traffic Dept., SP.S Ry."

Photograph of railroad construction workers standing in an unfinished rock cut. Steep rock cliffs rise all around them and one person stands on the cliff above them. Railroad tracks, still under construction, end at the rock face behind the workers. Taken on the Washington side of the Columbia River Gorge. Handwritten note on the back of the print reads, "Rock cut at 1488." Second note reads, "MP 52.5 near Carson, tracks at left to river's landing."

Photograph of 4 railroad construction workers standing in an unfinished rock cut. Steep rock cliffs rise all around them. Railroad tracks, still under construction, end at the rock face behind them. Taken on the Washington side of the Columbia River Gorge. Handwritten note on the back of the print reads, "Rock cut at 1488 near Carson landing." Second note reads, "Return to Traffic Dept., SP.S Ry."