In recent years, oil and gas activity in the United States has increased and spread to new areas. This has boosted the economy and improved the nation’s energy security, but it also has prompted concerns that the activity might cause local inconvenience or harm to the environment. Many local governments have responded to such concerns by enacting ordinances that purport to prohibit or regulate oil and gas activity or to restrict where it can be conducted. These ordinances potentially conflict with state laws governing oil and gas activity, and this has led to disputes and litigation in several states regarding the enforceability of the local ordinances. To resolve such disputes, courts analyze the state and local laws using a preemption analysis.