President Donald Trump is expected to take action on Friday to open more offshore areas to oil and gas drilling, in part by reversing his predecessor's attempt to permanently protect large swaths of U.S. waters.
The president plans to sign an executive order instructing Interior Department Secretary Ryan Zinke to review and in all likelihood throw out President Barack Obama's plans for federally administered waters.
The reversal will not come overnight. Bureaucrats must grind through a multiyear process to overturn Obama's plans, and the executive action tees up a widely anticipated legal battle over executive authority.
Here are three paths Trump can take — and the challenges to each.