In the late 2000s, slaughterhouses across the Amazon entered into a series of agreements designed to reduce the environmental impact of the local cattle sector. In this research, we analyze the impact of these agreements using a novel dataset showing the location of cattle vaccinations in 2014. In total, we estimate that more than half of the cattle herd in Novo Progresso was vaccinated on ranchlands which were either located in protected areas, were deforested since the agreements were put into place, were subject to an official embargo due to a violation of environmental or labor laws, or were not registered in the state of Pará's Rural Environmental Registry. The results suggest that hundreds of thousands of cattle continue to graze on areas in Southwest Pará which were meant to be excluded, per the terms of the recent cattle agreements, from the supply chain in a key Amazon cattle frontier. Our results highlight the importance of developing new systems for monitoring cattle supply chains in remote areas of the Amazon.