They had been on a trapping expedition, but having met with nothing but disasters from the beginning, were now straggling back to St.Louis on foot.
The explorers proceeded at a leisurely pace that day and having gone into camp, observed three Indians drawing near, one of whom was a boy about a dozen years of age.

They were Cheyennes that had been out among the Pawnees to steal horses, but having met with no success, were returning home.

Catching sight of the white men, they unhesitatingly entered camp, confident of being treated well, as of course proved to be the case.

After supper one of the warriors drew a rude but correct map of the country around them, and gave it to Fremont.
On the first of July, while riding over a delightful prairie country, on the right bank of the river, a herd of buffaloes, numbering nearly a thousand, came up from the water and began slowly crossing the plain, cropping the grass as they went.

As the prairie was three miles broad only, a fine opportunity was given the hunters to charge before the animals could scatter among the hills.
The fleetest horses were quickly saddled and Carson, Fremont, and Maxwell prepared for the chase.