Helaman 4:7

and there they did fortify against the Lamanites, from the West Sea, even unto the East; it being a day’s journey for a Nephite, on the line which they had fortified and stationed their armies to defend their north country.

There they built defenses against the Lamanites. They built from the west sea to the east. It was a day’s walk for a Nephite. They put their armies on this line to protect their northern country.

There they built fortifications against the Lamanites, stretching from the west sea to the east—a day’s journey across the defensive line they’d established to protect their northern territory.