Since 1994, migrant fatalities on the Arizona Sonora Border have grown significantly as a result of prevention through deterrence policies ostensibly intended to prevent unauthorized migration by making it dangerous and even deadly to migrate. Building on a growing body of scholarship documenting migrant vulnerability, this article examines the political dimensions and possibilities of the Migrant Trail, a seventy-five-mile collective walk from Sásabe, Sonora, to Tucson, Arizona, that seeks to witness and protest the deadly conditions created by border policy. Drawing on intimate ethnography, I conceptualize the Migrant Trail as a space of encuentro (encounter) and by extension, a pedagogical space, that reveals the deadly consequences of United States border enforcement and the ways in which contemporary policies weaponize the desert to control migration. Initially organized in 2004, the annual walk is an autonomous political intervention that moves beyond mainstream liberal institutions and electoral politics to provoke a series of critical realizations and insights and a new way of doing politics. Through this embodied experience, walkers become frontline observers and political actors. By publicly remembering those who have died crossing, they aim to interrupt state policies that actively disappear people in transit by disappearing their stories with them.