The green grass sprang up on the mounds, the animals rejoiced and began even to prance in their new-found vigor.

The winter had gone and the time for the singing of birds had come.
The trappers were in need of certain supplies, before they could advantageously set out on their spring hunting tour.

They therefore sent two of their party to obtain these supplies at Fort Laramie, which was one or two hundred miles south of them, on the Platte river.

They did not return.

They were never heard from.