A cable trough comprising: a tray including a tray portion extending along a generally horizontal plane and having two opposite side edges (30, 32), a first side wall portion extending along one side edge of the tray portion on a plane generally perpendicular to the plane of the tray portion, the first side wall portion having at least two vertically aligned openings formed therein at one end of the first side wall portion and at least two vertically aligned openings formed therein at an opposite end of the first side wall portion, and a second side wall portion extending along the other side edge of the tray portion on a plane generally perpendicular to the plane of the tray portion, the second side wall portion having two vertically aligned openings formed therein at one end of the second side wall portion and at least two vertically aligned openings formed therein at an opposite end of the second side wall portion; a first side wall including a plurality of vertically aligned openings formed therein at one end of the first side wall and a plurality of vertically aligned openings formed therein at an opposite end of the first side wall, the first side wall being configured to be secured to the first side wall portion of the tray with at least two fasteners at a selected elevation along a height of the first side wall; and a second side wall including a plurality of vertically aligned openings formed therein at one end of the second side wall and a plurality of vertically aligned openings formed therein at an opposite end of the second side wall, the second side wall being configured to be secured to the second side wall portion of the tray with at least two fasteners at a selected elevation along a height of the second side wall; characterized in that: the first side wall further includes a first horizontal flange portion extending from a lower edge of the first side wall, the first horizontal flange portion being configured to engage a surface; and the second side wall further includes a second horizontal flange portion extending from a lower edge of the second side wall, the second horizontal flange portion being configured to engage a surface. a tray including a tray portion extending along a generally horizontal plane and having two opposite side edges (30, 32), a first side wall portion extending along one side edge of the tray portion on a plane generally perpendicular to the plane of the tray portion, the first side wall portion having at least two vertically aligned openings formed therein at one end of the first side wall portion and at least two vertically aligned openings formed therein at an opposite end of the first side wall portion, and a second side wall portion extending along the other side edge of the tray portion on a plane generally perpendicular to the plane of the tray portion, the second side wall portion having two vertically aligned openings formed therein at one end of the second side wall portion and at least two vertically aligned openings formed therein at an opposite end of the second side wall portion; a first side wall including a plurality of vertically aligned openings formed therein at one end of the first side wall and a plurality of vertically aligned openings formed therein at an opposite end of the first side wall, the first side wall being configured to be secured to the first side wall portion of the tray with at least two fasteners at a selected elevation along a height of the first side wall; and a second side wall including a plurality of vertically aligned openings formed therein at one end of the second side wall and a plurality of vertically aligned openings formed therein at an opposite end of the second side wall, the second side wall being configured to be secured to the second side wall portion of the tray with at least two fasteners at a selected elevation along a height of the second side wall; characterized in that: the first side wall further includes a first horizontal flange portion extending from a lower edge of the first side wall, the first horizontal flange portion being configured to engage a surface; and the second side wall further includes a second horizontal flange portion extending from a lower edge of the second side wall, the second horizontal flange portion being configured to engage a surface. the first side wall further includes a first horizontal flange portion extending from a lower edge of the first side wall, the first horizontal flange portion being configured to engage a surface; and the second side wall further includes a second horizontal flange portion extending from a lower edge of the second side wall, the second horizontal flange portion being configured to engage a surface.