ANCHORAGE — Interior Secretary Ken Salazar unveiled a proposed management plan Monday for a vast petroleum reserve on Alaska’s North Slope and the state’s senior senator immediately pronounced it too restrictive.

Republican Lisa Murkowski said the Obama administration picked the most restrictive management plan possible for the National Petroleum Reserve-Alaska, an area created by President Warren Harding in 1923 that covers 23 million acres, roughly the size of Indiana.

The environmentally sensitive Teshekpuk Lake area, renowned for its habitat for migratory birds, including black brant, Canada geese and greater white-fronted geese, already was under a 10-year deferral for additional study, she said.

“This alternative goes vastly beyond that, putting half of the petroleum reserve off limits,” Murkowski said. “This decision denies U.S. taxpayers both revenue and jobs at a time when our nation faces record debt and chronic unemployment.”

At a press conference, Salazar said the proposal balances wildlife protection, villagers’ subsistence requirements and the nation’s need for additional petroleum.

About 11.8 million acres would be available for leasing, including most land projected to contain oil reserves, Salazar said.

The proposal provides a potential route for a pipeline that could transport oil from offshore leases in the Chukchi Sea east to the trans-Alaska pipeline, which bisects the state north to south.

The potential for development was balanced with protections for the region’s wildlife, Salazar said.

“It is an iconic place on our Earth,” Salazar said.

The wildlife includes the 325,000 animals in the Western Arctic Caribou Herd and the 55,000 animals in the Teshekpuk Caribou Herd, sources of subsistence food for 40 northern and western Alaska Native villages.

The Utukok River Uplands special area would protect calving grounds and an area where caribou seek relief from insects.

The plan would restrict leases in Peard Bay and Kasegaluk Lagoon, which is important habitat for seals, polar bears and other marine mammals, Salazar said. Land along the Colville River would be restricted to protect raptors.

Salazar said a final decision on the management plan could be made by December.

Sen. Mark Begich, D-Alaska, said the new preferred alternative appears to close off options for building a pipeline across the reserve.

Erik Milito of the American Petroleum Institute said the announcement leaves domestic energy resources, jobs and government revenue off the table.

“The public and the oil and natural gas industry continue to support U.S. energy development,” he said. “However, the Administration continues to prevent, delay and obstruct development of these important resources, and puts off jobs for another day.”

Representatives of environmental groups were encouraged by the choice.

“The areas most important to wildlife must be kept off-limits to development,” said Athan Manuel of the Sierra Club.

National Audubon Society President and CEO David Yarnold said the plan shows that Americans can protect nature on lands designated for energy production.

“Some places really are too precious to drill, and there’s no better example than the Teshekpuk Lake area, one of the planet’s most prolific bird nurseries,” he said.