The quartermaster arranged for the transportation, pack mules, etc.

But General Sheridan, under whose direction the scientists were proceeding, always believed in my ability to select good horses from a quartermaster's herd.
In a few days Professor Marsh and his companions arrived.

The Pawnee Scouts, then in camp, had a year before unearthed some immense fossil bones, so it was decided that Major North, with a few of these scouts, should also accompany the expedition.

Professor Marsh had heard of this discovery, and was eager to find some of the same kind of fossils.
Professor Marsh believed that the Basin would be among the last of the Western lands to be settled.

The mountain wall which surrounded it would turn aside pioneers going to Montana or northern Oregon.