Looking at lines in US-American Land Art means to investigate various, sometimes even diverging practices of line-making. In many site-specific pieces, traces are cast on the ground, either by removal or by accumulation of material, often resulting in a line the viewer can follow towards another point into the distance, involving the visitor in a self-reflexive, phenomenological experience. However, lines are also understood in terms of their relation, as grids and networks of reference, in which site-specific experience is transformed into a photograph as an indexical trace of the work. In all those examples, lines involve a spatio-temporal movement, a following of the lines by walking or by a process of thinking the lines of reference. But ultimately, the more conceptual pieces in Land Art also introduce a sense of breaking or wandering away from the lines, emphasizing void networks and the continuous process of dematerialization, addressing the inability of the viewer to follow any line. The article will show that the lines in Land Art thus shift between a modern perception of the straight line as well as a postmodern experience of dislocation and broken threads.