Lewis and Clark's Columbia River
Lewis & Clark's Columbia River - "200 Years Later"
"Tenasillahe Island"
Includes ... Tenasillahe Island ... Red Slough ... Columbian White-tailed Deer National Wildlife Refuge ...
Image, 2012, Tenasillahe Island from Puget Island, click to enlarge
Click image to enlarge
Tenasillahe Island as seen from Puget Island. Image taken September 17, 2012.

Tenasillahe Island ...
Tenasillahe Island is located in the middle of the Columbia River at River Mile (RM) 35, just downstream of Puget Island. The Clifton Channel separates it from the Oregon shore and the mainstream Columbia separates it from the Washington shore and the Julia Butler Hansen Refuge for Columbian White-tailed Deer. Tenasillahe is one of the many islands in the Refuge. On the downstream side of Tenasillahe is located Welch Island, one of the many islands in the Lewis and Clark National Wildlife Refuge. The Red Slough separates the two islands.

Early Tenasillahe Island ...
Tenasillahe Island's name is composed of two Chinook-jargon words, "tenas," meaning small, and "illahe," meaning land.

According to "Oregon Geographic Names" (McArthur and McArthur, 2003, Oregon Historical Society):

"Tenasillahe Island (Clatsop) ... The name Tenasillahe is composed of two Chinook jargon words, tenas, meaning small or little, and illahe, meaning land, hence, "little land". There are many ways of spelling Chinook words, but the USBGN, as a matter of standardization, has adopted the form shown at the head of this paragraph. This island is low and marshy in places, which doubtless accounts for the Indian name. Maps prepared by Lewis and Clark show this and other islands nearby in the Columbia River marked marshy islands, but the expression was apparently not used as a geographic name. Lt. W.R. Broughton passed Tenasillahe Island on October 25, 1872, and describes it as a "long, sandy, shallow spit." His report on this part of the Columbia River is not entirely clear, but it may be that he camped on the island that night, as he mentions "the dampness of the situation." Wilkes used the name Kathlamet for this island, a form of Cathlamet."

In 1792 Lieutenant William Broughton, of the George Vancouver expedition, passed by Tenasillahe Island on October 25, 1792.

In 1805 and 1806, Lewis and Clark called Tenasillahe Island and a nearby smaller island (today's Welch Island) the "Marshy Islands", a descriptive name rather than a naming of the islands.

In 1841, Charles Wilkes of the U.S. Exploring Expedition used the name "Katalamet I." for Tenasillahe Island.

The 1856 U.S. Bureau of Land Management's Cadastral Survey (tax survey) map for T9N R6W, shows today's Welch and Tenasillahe Islands, with Tenasillahe Island labeled "Tenas Illahe Island". Welch Island and Red Slough are depicted but not identified.

The 1892 U.S.C. & G.S. Topographic "Columbia River Sheet 3" shows "Tenasillihee I.". On the east side of the island is the "Tenasillihee Fishery".

Edmund S. Meany wrote in "Origin of Washington Geographic Names" (1923, University of Washington Press):

"Tenas Illihee Island ... west of Puget Island in the Columbia River, in the southern part of Wahkiakum County, charted by that name on the United States Coast and Geodetic Survey Chart 6152. The Wilkes Expedition, 1841, charted it as "Katalamet Island." (Hydrography, Volume XXIII, Atlas, chart 70). The Chinook Jargon words Tenas Illihee mean "Little place" or "little home."

In 1893 the U.S. Board of Geographic Names made "Tenasillihee Island" official.

In 1914 the U.S. Board of Geographic Names made "Tenasillahe Island" official, over variants "Tenasillihee", "Tennassillihii", "Tenas Illihee", "Tenas-Illihee", and "Tenasillahe".

Views ...

Image, 2012, Columbia River from Clifton Road, Oregon, click to enlarge
Click image to enlarge
Columbia River as seen from the Clifton Road, Oregon, with Tenasillahe Island. In the distance Tenasillahe Island is to the left and Puget Island is to the right. The settlements of Clifton would be left (downstream) and Bradwood would be right (upstream). Clifton Channel is in the middleground, left. Jetty visible on right juts off Tenasillahe Island. Image taken September 22, 2012.

Tenasillahe Island, etc.

  • Red Slough ...

Red Slough ...
Red Slough, roughly 1.4 miles long, separates Welch Island from Tenasillahe Island, approximately at Columbia River Mile (RM) 35. The Oregon community of Clifton is located south of Red Slough and the Washington community of Skamokawa is located north of Red Slough.

Red Slough has gone by two names -- "Multnomah Slough" and "Red Slough".

"Multnomah Slough" appeared on maps and charts since the late 1800s. The 1875 "Columbia River Sheet No.2" U.S. Coast Survey Plate No.1299, and the 1878 "Columbia River, Sheet No.3" U.S. Coast and Geodetic Survey Chart No.641 show "Multnomah Slough".

"Red Slough" appeared on a 1948 NOAA Chart #6152, and in 1981 a USGS field investigation found "Red Slough" was the name used by residents living in the area. As early as 1885 "Red Slough" ("Red's Slough") was in usage.

"BOAT FOUND. On the 30th of August, between Bay View and Fisherton, one small fishing boat, sail and oars complete. Said boat was drifting down the river with sail set. Owner can have same by proving property and paying charges. John Vantura, Red's Slough, Tenas Illahe Island, August, 31st, 1885." [The Daily Morning Astorian, September 3, 1885, courtesy Historic Oreogn Newspapers Archives, University of Oregon Libraries, 2019]

"On Saturday last Charles Rande, of Klatskanie, Columbia county, came to this city and swore out a complaint charging Peter Marks with stealing a new net and other property, valued at $700, from his, Rande's barn. A warrant was issued by Deputy Prosecuting Attorney C.J. Curtis, for the arrest of Marks, who was then, Rande stated, at Red Slough, near Clifton ... [The Daily Morning Astorian, December 6, 1894, coutesy Historic Oregon Newspapers Archives, University of Oregon Libraries, 2019]

In 1980 the U.S. Board of Geographic Names made "Multnomah Slough" the official name for this slough.

In 1986 the U.S. Board of Geographic Names changed the official name to "Red Slough", citing confusion with "Multnomah Channel", located 60 miles upstream.

From the Journals of Lewis and Clark ...

Clark, November 7, 1805 ...

Journey to the PacificReturn to

*River Miles [RM] are approximate, in statute miles, and were determined from USGS topo maps, obtained from NOAA nautical charts, or obtained from the U.S. Army Corps of Engineers website, 2003

  • Historic Oregon Newspapers Archives, University of Oregon Libraries, 2019;
  • McArthur, L.A., and McArthur, L.L., 2003, "Oregon Geographic Names", Oregon Historical Society Press;
  • Meany, E.S., 1923, "Origin of Washington Geographic Names", University of Washington Press;
  • U.S. Geological Survey Geographic Names Information System (GNIS) database, 2006, 2019;
  • Washington State Historical Society website, 2004, "Lasting Legacy";

All Lewis and Clark quotations from Gary Moulton editions of the Lewis and Clark Journals, University of Nebraska Press, all attempts have been made to type the quotations exactly as in the Moulton editions, however typing errors introduced by this web author cannot be ruled out; location interpretation from variety of sources, including this website author.
August 2016