Enhanced oil recovery has generated an immense and growing market for carbon dioxide (CO2), which has uses in manufacturing, medical, and industrial settings. In the next 30 years, these combined end-uses will necessitate a three- to fivefold expansion of existing CO2 transportation infrastructure in the United States. A more flexible, extensive, and integrated CO2 pipeline network is necessary to accommodate this growing demand. Like oil pipelines and electric transmission lines, CO2 pipelines are sited according to state law, which determines where and how they are routed and the conditions under which they will be operated. This Article provides an overview of CO2 pipeline regulation, a state-by-state comparison of siting, routing, and operation laws, and a case study of the federal and state permitting required for a recent CO2 pipeline. It closes with suggestions for state legislatures looking to encourage the development of CO2 transportation infrastructure.