The Outdoor Museum, in Joshua Tree, California, is an assemblage of the assemblages made by the artist Noah Purifoy between 1989 and 2004. The Museum provides an exemplary site for thinking about theatrical assemblages, the topic of this paper and of a larger project in its early stages. From Theater Piece No. 1 or “Untitled Event” presented at Black Mountain College in 1952—the collaboration between John Cage, Merce Cunningham, Robert Rauschenberg, David Tudor, Charles Olson, M. C. Richards, and others—to the present, performance and theatricality have been central to the history of artistic assemblages; the aesthetics of assemblage, meanwhile, have been central to experimental theater. What happens where assemblages verge on theater and theater takes on assemblage? How are assemblages legible, especially when they insist on discreteness of and the non-relation between the things they gather? The Outdoor Museum provides an example to think through these questions concretely. The curators supply a map of the grounds of the museum, with the names of the separate pieces, but there is no prescribed way to move through the assemblages. One striking path a visitor may follow through the Outdoor Museum links a set of theatrical sites. Most strikingly, one of the assemblages is called “Adrian’s Little Theater”; this assemblage does have the structure of a small theater. Other assemblages contain groupings of chairs for spectators, and so on. One of the final pieces is simply called “Gallows”: in this context, the scaffold, inspired by a Clint Eastwood movie, is distinctly organized for spectators, as potential theater. That is, these pieces constellate around theater and spectatorship. This theatrical path produces one way of understanding the Outdoor Museum. The argument of this paper will be that the Outdoor Museum invites interpretation of a kind that acknowledges its own permanent provisionality without surrendering a claim to importance as interpretation.