The Sierra Nevada is presented as a practical barrier in Ish’s post-disaster plans for travel across the United States. Though he recalls the landscape through old road maps, the mountains are not described as a destination or crossed in the narrated passage; their importance lies in how they narrow the routes available to a traveler facing damaged roads and uncertain conditions.

A Barrier to Eastward Travel

When Ish considers whether an automobile could carry someone a considerable distance, he turns to the problem of choosing a route. His geographical knowledge leads him to expect that roads crossing the Sierra Nevada will be completely blocked by fallen trees and landslides. He thinks roads to the north are likely to face similar obstructions, so the mountain range shapes the journey before it begins: the most direct-looking paths are not necessarily usable.

The Southern Alternative

Ish judges that the best chance of getting east lies through more open country to the south, along the route he had taken to New York City long before the disaster. He hopes that desert roads may remain comparatively intact, while recognizing that the bridges over the Colorado River could either still be standing or have fallen. The route remains a proposal, not a completed crossing; its feasibility can only be determined by going out to inspect it. Beyond the river, Ish expects the mountains to present less difficulty, with the Rio Grande near Albuquerque as the next major obstacle and open plateau country beyond the Sandia Mountains.

Narrative Significance

The Sierra Nevada’s role is defined by the contrast between remembered geography and altered infrastructure. Ish can use his old knowledge to imagine a route, but maps cannot tell him whether fallen trees, landslides, or damaged bridges have made it passable. The mountains therefore mark both a physical obstruction and a limit on what planning alone can establish: travel depends on testing the landscape directly.