Like the Ulgos, the Dryads predate the western migration of civilized men into the west.

In their preface they characterize Lienhard's text as "one of the three classical reports of the great western migration of 1846."

This new enterprise was to become one of the principal trading posts for the western migration, established specifically to serve the wagon trains heading to the far West.

The California Gold Rush of 1848-49 further spurred western migration.

The Dust Bowl of the mid-1930s impoverished many farming communities and spurred a new wave of western migration.

In addition, the foraging and hunting by settlers traveling on the western migration trails took additional resources away from the Shoshone.

The western migration is smaller and less dramatic.

First book in a projected four-volume study of the course and impact of western migration.

No evidence for the occurrence of this blood type extends beyond 900-1,000 years ago, when a large western migration of eastern peoples took place.

Instead, the government likens the current campaign to the western migration of American settlers in the 19th century.