The Colorado River is a key obstacle and landmark on the eastward journey described in the novel. Its importance lies less in a physical portrait of the river than in the uncertain state of the bridge across it: a crossing that could either keep the travelers on their planned route or force them to find another way.

A crossing on the eastern route

When Ish considers a journey east, he favors the southern route through the desert, recalling a road he had taken on an earlier trip to New York. The Colorado River marks a consequential point along that route. Its bridges might still be standing, he reasons, or they might have fallen; only a journey could settle the question.

Ish’s route plan places the river between the desert roads and the more difficult country beyond. Past the Colorado, he expects the mountains to present no great obstacle, with the Rio Grande near Albuquerque as the next major river crossing. The Colorado is thus not an isolated destination but one of the first tests in a much longer passage across the continent.

Ish’s contingency plan

When he briefs the boys for their expedition, Ish makes the bridge’s uncertain condition part of their instructions. If the Colorado River bridge is intact, they can use it; if it is not, they should turn north and try the road across Boulder Dam. He also shows them how to read their maps and work out alternatives when the route ahead is blocked.

The advice reflects the practical limits of travel after the Disaster. Ish expects the jeep to get through occasional obstacles, but the travelers cannot assume that every piece of inherited infrastructure remains usable. At the river, preparation means having a second crossing in mind rather than treating the planned route as certain.

The bridge encountered

The expedition’s report resolves the uncertainty: the Colorado River bridge is shaky, but still passable. The boys have therefore crossed without needing Ish’s northern alternative. Their account confirms both the survival and the deterioration of the bridge, a structure usable enough to carry the journey forward but no longer something to trust without qualification.

From Los Angeles, they have followed U.S. Route 66 east across a desert highway that remains largely open, with occasional stretches of blown sand and scattered tire blowouts. The river crossing continues that pattern: the old route has not vanished, but passage depends on assessing what remains and adapting to its condition.

Narrative significance

The Colorado River gives Ish’s continental plans a concrete point of uncertainty. On the map, it is a line to cross; in practice, its bridge may be broken, sound, or somewhere between the two. The difference matters because his aim is not simply to reach the East, but to find other communities and learn how they are rebuilding.

When the boys return with news that the bridge was passable, their experience echoes Ish’s own earlier journey across the same desert route. The river therefore links his remembered knowledge to the younger travelers’ firsthand report. It also shows the novel’s recurring tension between inherited systems and the work of living with their failures: a surviving bridge can still serve, but only after people discover its condition and judge whether it can be trusted.