If fully utilized, Interior predicts the zones could produce 23,700 megawatts of solar energy, enough to power 7 million homes.
Senate Majority Leader Harry Reid (D-Nev.) joined Salazar in finalizing the plan in Las Vegas.
Reid and President Obama have been outspoken proponents of solar power, especially in the Southwest, with Obama often mentioning solar power’s potential in campaign stops.
The domestic solar industry has struggled recently, as it is engaged in a trade battle with China.
The administration fired the most recent volley Wednesday by affirming tariffs on Chinese imports. The Commerce Department determined Chinese solar panels were sold below fair value and that its solar businesses unfairly received direct government support.
The development program approved Friday cuts some up-front costs for developers, as the federal government already has performed National Environmental Policy Act assessments for the sites.
Lack of electrical infrastructure is one of the main roadblocks for potential solar power hotbeds, such as Arizona. The plan would work to connect transmission lines, which carry large amounts of power from generators to distribution utilities, to the solar zones.
The League of Conservation Voters applauded the plan, saying it would help reduce greenhouse gas emissions and create clean energy jobs.
“President Obama’s plan is a big deal for solar energy. We commend his Administration for developing an innovative path forward for tapping America’s abundant solar resources on public lands in the Southwest while protecting environmentally sensitive areas," Gene Karpinski, the group's president, said in a statement.
— This story was updated at 3:32 p.m.