Gunpowder was just about essential to life and survival in the West. The loss of your powder supply, through use or accident could mean starvation or death.
Small quantities of gunpowder was also given as a gift to the Indians when trading and making talks.
Here are a few excerpts regarding gunpowder.

From Robert Campbell:
The powder brought up in the Summer of 1827, was of an inferior quality.
It was so bad, that it became a saying, that the men would snap the gun and lay it down on the
ground, before it went off.

While there, Fitzpatrick joined us in a famished condition. He lost his powder horn, and had
nothing to eat for many days.

From W.A. Ferris:
The following afternoon we passed a Pawnee village situated on the opposite bank of
the river, and sent, as customary, a present of tobacco, powder, balls etc., to these tribute‑taking
lords of forest, field and flood, the heart of whose wild dominion we are now traversing.

The same evening one of our men by the name
of Perkins, was severely burned by the accidental explosion of his powder horn.

The bodies of the two dead men were found the next day; both had been stripped
and scalped. Beside one of them lay a gun, broken off at the breech, and charged with two balls
without powder

From Wilson Price Hunt who travelled with the Astorians in 1811
The chief came to meet us. He received us amicably, led us to his tent, and pointed to a spot convenient
for our camp. I gave him presents of tobacco, knives, and some trifles to distribute among
his people. To him personally I gave a piece of scarlet cloth, some powder, bullets, and other
items.

From James O. Pattie, late 1820's:
Our agreement was to wait
until she [grizzly sow] came within 30 yards, and then he was to give her the first fire. He fired, but the powder
being damp, his gun made long fire, whence it happened that he shot her too low, the ball passing
through the belly, and not a mortal part. She made at him in terrible rage.

Lost Green horn by Alfred Jacob Miller

Interesting k snow. I have a related question for you. As a child, I remember a show about mountain men that briefly mentioned that they would occasionally make their own powder using duck manure. Have you ever seen reference to that? I suppose that could be a source for the potassium nitrate, but even as a kid, it seemed to me that producing your own powder in a wild environment would be quite the task.

I have not seen any references about making powder in the "frontier". Like you, I suppose duck manure could work.

I can do some more digging through my notes.

If you find anything I would love to hear about it. Thank you sir.

“She made at him in a terrible rage”…I just bet! Scary

Apparently you can't grow it "from seed". LOL.

From Rufus Sage:
The Blackfeet at first were friendly to the whites, and a very considerable trade in guns and ammunition
was carried on with them by the latter. Like most savages, they became great admirers
of the potency and use of gunpowder, and were quite curious to ascertain the process by which
it could be had independent of the whites. In answer to inquiries, they were informed it was the
seed of a species of grain, and might be multiplied in like manner to any extent by cultivation.
Accrediting the story and captivated with the idea of raising their own powder, a large quantity
was purchased for that purpose, which was carefully planted, in full expectation of an abundant
harvest.

I bet they were really upset when it didn't germinate.

Good stuff. Thanks for posting.