Near the site of the present city of Winnipeg, in the late summer of
1800, he and his expedition were much troubled by swarms of water
snakes. They were harmless but not pleasant in their familiarity, for
they entered the tents and took refuge in the explorers' beds; and as
they apparently came from their breeding places in Amerindian graves
which covered the remains of people who had died of smallpox in a
recent epidemic, they were additionally loathsome.

Smallpox indeed played a very important part in the historical
development of western North America. Prior to 1780 the Amerindian
tribes between the upper Mississippi and the Rocky Mountains, and
between the Saskatchewans and the Missouri, were numerous and warlike.
At first, about 1765, they received in very friendly fashion the
pioneer British traders and French Canadians who attempted to resume
the fur trade where it had been dropped by the French monopolists in
1760. But fifteen years afterwards, enraged at the violence and
wrongdoing of the British and Canadian traders, and maddened by strong
drink, they were planning a universal massacre of the whites, when
suddenly smallpox (introduced by the Spaniards into New Mexico) came
on them as a scourge, which destroyed whole tribes, and depopulated
much of western North America.

Alexander Henry had many adventures with the bison of the plains. Here
is one of them.

"Just as I came up to him at full speed and prepared to fire, my horse
suddenly stopped. The bull had turned about to face my horse, which
was naturally afraid of buffaloes, and startled at such a frightful
object; he leaped to one side to avoid the bull. As I was not prepared
for this I was pitched over his head, and fell within a few yards of
the bull's nose; but fortunately for me he paid no more attention to
my horse than to me. The grass was long, and I lay quiet until a
favourable opportunity offered as he presented his placotte. I
discharged both barrels of my double gun at him; he turned and made
one plunge toward me, but had not time to repeat it before he fell,
with his nose not more than three paces off.... I had to return on
foot as my horse had bolted."

At this place--near the Red River (the season September)--the country
swarmed with big game such as North America will never see any more:
enormous numbers of bison, of wapiti or Canadian red deer, moose or
elk, prong-buck, and of grizzly bears and black bears who followed the
herds t