Mammal

Fox Squirrel

Sciurus niger
Mammal Along the Ohio River near present-day Cincinnati, Ohio New to Western Science
Fox Squirrel

Photo: Wikimedia Commons, CC BY-SA

Common Names
Eastern Fox Squirrel
Habitat
Deciduous forests, river bottoms, and woodlands along the Missouri and Ohio Rivers
First Observed
1803-09-11
Observed At
Along the Ohio River near present-day Cincinnati, Ohio

One of the earliest wildlife encounters of the expedition occurred when Lewis’s dog Seaman caught squirrels swimming across the Ohio River in September 1803 – a remarkable mass migration event. Lewis later noted various squirrel species throughout the journey, including the “whistleing squirrel” (prairie dogs or ground squirrels) of the plains and a squirrel “of the speceis common to the Rocky Mountains.” The squirrel swimming migration was one of the most vivid early journal entries.

Recent sightings

Where it’s being seen today

12 research-grade iNaturalist observations between 2024–2026. Most recent: 2026-02-15. Sourced from Terrain360 trail captures, cached locally.

Journal References

15 journal entries mention Fox Squirrel

Sep 11 1803
Seaman Catches Squirrels Swimming Across the Ohio
...down the Ohio River, they encountered large numbers of gray squirrels swimming across the river—a mass migration phenomenon well documented in the early American ...
Sep 7 1804
John Ordway: September 7, 1804
...esembles them nearly except the tail which is like a Ground Squirrel, they will Stand on their hind feet & look &. C. we Camped on the South Side near the Steeple of th...
Mar 31 1805
Fort Mandan, preparing for departure — Patrick Gass: March 31, 1805
...t colour. Yester- “day: “onélof the men caught a small squirrel, like a ground squirrel, but of a more dun colour, and more — - spotted. We finished the boat thi...
Apr 14 1805
Lewis: April 14, 1805
... on the Lard. side, there was a large village of burrowing squirrels. I have remarked that these anamals generally celect a South Easterly exposure for their residenc...
Jun 5 1805
Lewis: June 5, 1805
... we saw the largest collection of the burrowing or barking squirrels that we had ever yet seen; we passed through a skirt of the territory of this community for abou...
Jul 8 1805
Lewis: July 8, 1805
... distinct species. the men also brought me a living ground squirrel which is something larger than those of the U States or those of that kind which are also common ...
Jul 8 1805
Great Falls Portage — Patrick Gass: July 8, 1805
... of a light colour. Yesterday one of the men caught a small squirrel, like a ground squirrel, but of a more dun colour, and more spotted. We finished the boat this even...
Sep 1 1805
North Fork Salmon River, impassable route — Patrick Gass: September 1, 1805
...HE forenoon we killed some pheasants and ducks, and a small squirrel. In the afternoon we had a good deal of rain, and the worst road (if road it can be called) that wa...
Sep 2 1805
North Fork Salmon River, impassable route — Patrick Gass: September 2, 1805
...HE forenoon we killed some pheasants and ducks, and a small squirrel. In the afternoon we had a good deal of rain, and the worst road (if road it can be called) that wa...
Oct 21 1805
Columbia River near Wallula Gap — Patrick Gass: October 21, 1805
...e saw among them some small robes made of the skins of grey squirrels, some racoon skins, and acorns, which are signs of a timbered coun- try not far distant. Having pr...
Oct 26 1805
Celilo Falls and The Dalles portage — Patrick Gass: October 26, 1805
...the falls. Some hunters went out and killed 6 deer and some squirrels. In the after- noon about 20 of the natives came to our camp (among whom were the head chiefs of t...
Oct 27 1805
Celilo Falls and The Dalles portage — Patrick Gass: October 27, 1805
... evening our hunters came in and had killed 4 deer and some squirrels. The wind blew hard all this day.
Nov 18 1805
Patrick Gass: November 18, 1805
...In the evening our hunters came in with a deer, 2 brants, a squirrel, a hawk, and a flounder, which the tide had thrown on a sand-bar. The Indians still remained with u...
Dec 21 1805
Building and occupying Fort Clatsop — Patrick Gass: December 21, 1805
...e saw among them some small robes made of the skins of grey squirrels, some racoon skins, and acorns, which are signs of a timbered coun- try not far distant. Having pr...
Dec 27 1805
Fort Clatsop, salt works established — Patrick Gass: December 27, 1805
... evening our hunters came in and had killed 4 deer and some squirrels. The wind blew hard all this day.

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