The Sierra Club declared open season on Interior Secretary James G. Watt yesterday, announcing a nationwide petition drive to collect a million signatures this summer demanding his ouster.

"We're trying to provide a way for an outraged public to express itself to those federal officials closest to them, namely their representatives in Congress," said Michael McCloskey, executive director of the conservation and environmental organization at Sierra headquarters in San Francisco. "The members of Congress can then express to the administration how their constituents feel."

The petition charges that Watt is "representing private economic interests rather than following the laws" and is "sabotaging conservation goals supported by the vast majority of the American people." It asks members of Congress to make Watt's removal "your highest priority" and to "resist legislation embodying his policies."

There is no official officer. McCloskey said Sierra Club telephones have been ringing off the hook since Watt took office with frustrated callers asking what can be done. The drive, he said, will channel that feeling into a "politically comprehensive form and will organize people to take action in the next election."

At a press conference, McCloskey charged that Watt deserved removal for ending parkland acquisition, opening marine wildlife sanctuaries to offshore drilling, downgrading reviews of lands being considered for designation as wilderness areas, "using the budget process to make policy decisions," and abolishing the Heritage Conservation and Recreation Service, among other acts.

Watt's office responded that the secretary "strongly believes he is in the mainstream of the environmental movement. He feels that environmental organizations should support his approach because he favors orderly development of needed natural resources" as a way to "prevent crash development under crisis conditions" later on.

David Brower, chairman of Friends of the Earth, and Charles Warren, a former chairman of the Council on Environmental Quality, were in San Francisco to be among the first to sign the petition. McCloskey said the 200,000-member Sierra Club anticipated little difficulty in obtaining the million signatures by summer's extremist," he said. "People are champing at the bit to get rid of him."