SAN DIEGO (AP) — A sweeping plan released Tuesday to regulate development of renewable energy in Southern California deserts designates nearly 400,000 acres for potential solar, wind and geothermal plants and millions more acres for conservation and recreation.

The long-awaited blueprint identifies 388,000 acres for potential development of federal land in largely agricultural areas, much of it along Interstate 10 west of Blythe near the Arizona border and in Imperial Valley, a region of 175,000 people that has historically suffered high unemployment.

It also sets aside 5.3 million acres for conservation and 3.6 million acres for recreation.

The plan carves up roughly 10 million acres in the Mojave and other deserts that are overseen by the U.S. Bureau of Land Management. The region is home to Joshua trees, desert tortoises, lizards, bighorn sheep and other wildlife.

“This strategy provides effective protection and conservation for wildlife, recreation and cultural resources, while encouraging streamlined renewable energy development in the right places,” U.S. Interior Secretary Sally Jewell said.

In March, state and federal regulators decided to focus on the 10 million acres after a more ambitious plan met resistance from local governments. The initial plan, unveiled in September 2014, involved 22.5 million acres across seven counties and generated about 16,000 public comments since its release.

Much of the 12.5 million acres remaining after the current plan is privately owned and will be considered on separate timetables.

Projects on private property would likely need to be approved by local governments, which clamored for a bigger say on the plan that attempts to bring order to a renewable-energy building boom in California’s deserts sparked during the first term of the Obama administration.

Regulators initially estimated that the plan would allow for projects that produce 20,000 megawatts by 2040, but the version released Tuesday allows for only a portion of that to be achieved.

The Nature Conservancy, an environmental advocacy group, called the latest version “an important step forward in developing a comprehensive and proactive plan to protect the climate, increase renewable energy and protect natural resources.”

The National Parks Conservation Association said the plan offers some important environmental protections but doesn’t remove the threat of renewable energy to desert national parks.