Photograph of construction workers on the Imperial Heading below Yuma, Arizona, [s.d.]. The workers sit along the wall of metal pipes on top of the heading with hats in hand. Below them appear to be concrete support walls with rectangular, metal frames lying between them. At the walls' bases broken planks of wood lie scattered across the jagged pieces of concrete and muddy puddles that cover the ground below. Wheelbarrows stand on the tops of these piles of debris while a long machine with what appears to be a hose extending from its side stand on the right.