Mammal
Bighorn Sheep
Ovis canadensis
Photo: Jakub Frys, CC BY-SA 4.0
Common Names
Bighorn / Mountain Ram
Habitat
S of Yellowstone Confluence
Conservation
Extinct
First Observed
1805-04-26
Observed At
Missouri River Breaks, near present-day Fort Peck, Montana
Audubon bighorn of Plains once thought a different species, or subspecies of mountain bighorn, now seen as extinct race.
Recent sightings
Where it’s being seen today
8 research-grade iNaturalist observations between 2013–2025. Most recent: 2025-06-04. Sourced from Terrain360 trail captures, cached locally.
Journal References
15 journal entries mention Bighorn Sheep
Apr
26
1805
Lewis: April 26, 1805
Friday April 26th 1805. This morning I dispatched Joseph Fields up the yellowstone river with orders to examine it as far as he could conveniently...
Apr
29
1805
Patrick Gass: April 29, 1805
...er seen, and on the top of the
highest we saw some Mountain sheep, which the natives say
are common about the Rocky mountains. These were the
first we had seen and w...
May
25
1805
Lewis: May 25, 1805
...d
small, the iris of a silvery colour much like the common sheep; the bone
above the eye is remarkably prominant; the head nostrils and division of
the upper lip ...
May
25
1805
Missouri River near Musselshell River — Patrick Gass: May 25, 1805
...killed three of what the French and natives call moun-
tain sheep; but they very little resemble sheep, except in the
head, horns and feet. They are of a dun colour ...
May
26
1805
Patrick Gass: May 26, 1805
...s. We saw few
animals of any kind, but the Ibex or mountain sheep. One of
our men killed a male, which had horns two feet long and four
inches diameter at the root.*...
May
27
1805
Missouri River, first view of Rocky Mountains — Patrick Gass: May 27, 1805
...bservations respecting
the country we have passed.
the real sheep in its wild and savage state. Perhaps it may be found to be exactly
the same: of which we find the ...
May
31
1805
Lewis: May 31, 1805
...anamals resort much to lodg, have the peculiar smell of the sheepfolds.
the party killed in addition to our hunt 2 buffaloe and an Elk. the river
today has been fr...
May
31
1805
Missouri River, first view of Rocky Mountains — Joseph Whitehouse: May 31, 1805
...in at dark had killed 1
black taild Deer 2 Ibex or mountain Sheep (rams) which had
handsom large horns. we took care of the horns in order to
take them back to the U...
Jun
1
1805
Missouri River near Marias River approach — Patrick Gass: June 1, 1805
...lands covered with cotton wood. We saw a number of
mountain sheep. Yesterday our men killed three of them,
that had remarkable large horns; one pair weighed 25 pound...
Jul
17
1805
Lewis: July 17, 1805
Wednesday July 17th 1805. The sunflower is in bloom and abundant in the river bottoms. The Indians of the Missouri particularly those who do not...
Jul
17
1805
Missouri River above Great Falls, Gates of the Mountains — Patrick Gass: July 17, 1805
...; and though they are almost perpendicular, we saw
mountain sheep on the very tops of them. We saw few other
animals to day. The general breadth of the river is 100 ...
Jul
27
1805
Lewis: July 27, 1805
Saturday July 27th 1805. We set out at an early hour and proceeded on but slowly the current still so rapid that the men are...
Aug
23
1805
Camp Fortunate, Sacagawea reunites with Cameahwait — Patrick Gass: August 23, 1805
...ind of shifts made
of the skins of these goats and mountain sheep, which come
down to the middle of the leg. Some of them have robes, but
others none. Some of the me...
Aug
24
1805
Lewis: August 24, 1805
...se people which have almost every appearance of the common
sheep. they inform me that they finde this animals on the high mountains
to the West and S. W. of them. ...
Sep
4
1805
Joseph Whitehouse: September 4, 1805
...sons froze
hard. the mountains covred with Snow. 2 mountain Sheep
[ 148 ]
1805] WHITEHOUSE’S JOURNAL
Seen by one of the men. we delayed untill about 8 oClock
A. M....