The crossing at what would become Jaeger City occupied a strategic necessity. The Colorado River in this stretch was broad, fast, and unfordable for most of the year. Anyone moving between California and the territories to the east — gold seekers, military supply trains, overland mail routes, emigrants — had to find a crossing, and Jaeger's ferry was one of the only options for a hundred miles.

L.J.F. Jaeger had come west during the California Gold Rush and recognized that the real fortune lay in moving people rather than panning for gold. He established his ferry operation in 1851 at the Yuma Crossing, where two granite outcroppings narrowed the river to its most manageable width. The settlement that grew up around the ferry landing took his name: Jaeger City, planted on the Sonora bank of the Colorado, just across from the growing fortifications of Fort Yuma.

Through the 1850s, Jaeger City grew. It had stores that supplied the fort and the travelers passing through, establishments catering to the steady traffic on the Southern Emigrant Trail, and the critical infrastructure of the ferry itself. The United States Army's presence at Fort Yuma on the California side meant that Jaeger City, positioned across the river on the Arizona-Sonora side, captured the commerce that military installations inevitably generate.

For much of this period, Jaeger City was the largest civilian settlement in the vicinity — larger than the embryonic town of Yuma itself would be for years. Its position at the crossing made it an obligatory stop on one of the main overland routes to California. Travelers who had endured weeks of desert travel reached the Colorado River here, paid their fare, crossed on Jaeger's ferry, and either continued west or rested at one of the settlement's establishments before doing so.

The same river that gave Jaeger City its reason for existence destroyed it completely in 1862. The Colorado River, fed by an exceptionally wet winter in the Rockies, rose beyond any level that the settlement had experienced. The Great Flood of 1862 was a catastrophic inundation across the Southwest, but its effects on the low-lying ground of the Yuma Crossing area were absolute.

Jaeger City was washed away. The buildings, the ferry infrastructure, the accumulated material of more than a decade of frontier commerce — all of it went under and did not come back. The settlement had been built on a floodplain, as most Colorado River settlements necessarily were, and the river reclaimed the ground it had always technically owned.

Unlike some flood-damaged towns, Jaeger City was never rebuilt. The site itself was altered by the flood, and whatever geography had made it attractive for settlement was rearranged by the force of the water. By 1862, the post office had closed and the settlement was finished.

Most ghost towns leave something: a crumbling foundation, a cemetery on a hill, a building frame resisting the desert. Jaeger City left nothing. The flood that ended it also erased its physical evidence, and more than 160 years of river sedimentation and agricultural development have buried whatever the flood left behind.

The site today is farmland and development on the Baja California side of the Colorado, near the crossing that Jaeger once dominated. His name survives in the regional history — the Neahr-Iaeger-Martinez House in downtown Yuma references his presence — and historians of the Yuma Crossing area record that the ferry existed, that the settlement existed, that both were significant. But the ground on which Jaeger City stood has long since been claimed by other purposes, and the river that erased it continues to flow, much diminished, through its engineered channel toward the sea.