Nancy Holt developed various ideas for her Locators through drawings. These three drawings from 1971, 1972, and 1973 show how she tested potential relationships between the apparatus of the Locator and corresponding Loci—the term she used for the focus point of vision. Holt was interested in the mechanics of vision and the difference position makes to seeing. Her elliptical Loci form perfect circles when viewed through the Locator.

In the summer of 1972, Nancy Holt presented Crossed Locators at 10 Bleecker Street in New York. Crossed Locators comprises four Locators arranged in two pairs across the room. Looking inward, each pair focuses on the Locator opposite it. Looking outward, they frame a series of focal points: a circular hole cut into a boarded-up window exposing bars and a brick wall; a wall of peeling paint with a circle outlined in chalk; a circular mirror; and a view of people walking on the street outside.