Recently, the states and federal agencies have clashed in a number of environmental rulemakings and subsequent litigation over those rules. These disagreements have raised a host of important legal and policy questions, including the proper balance of power between the states and the federal government and the communication process and overall relationship between the states and federal agencies. Recently filed litigation challenging the Stream Protection Rule, 81 Fed. Reg. 93,066 (Dec. 20, 2016), would prompt judicial review of many of these issues. But the likelihood of administrative or congressional action on this rule (through the Congressional Review Act) could preclude judicial input on these questions for now. If the rule is ultimately withdrawn or overturned, the manner in which it is may also present important federalism questions. Further complicating this process are two motions to intervene in two of these cases, filed by several environmental groups to defend the final Stream Protection Rule from being vacated or weakened.