This bill revises provisions governing citizen suits against the Department of the Interior or the National Oceanic Atmospheric Administration that allege a failure of the relevant department to perform its duties related to an endangered species or threatened species. Interior must publish the complaint in a citizen suit within 30 days of being served. Affected parties must be given a reasonable opportunity to intervene in the suit. If affected parties intervene, the court must refer the action to a mediation program or magistrate judge to facilitate settlement discussions. The court is prohibited from awarding litigation costs in such citizen suits that are settled. Interior must provide notice of a proposed settlement to each affected state or county. A settlement may not be approved if states or counties object.