Schwarzenegger pressing state regulators to allow power line proposed through Anza-Borrego Desert State Park

Proposed for Anza-Borrego Desert State Park, the project puts Schwarzenegger again at odds with environmentalists -- and some state officials -- who believe he is allowing California's unrivaled collection of public preserves to be threatened.

The latest controversy follows the governor's proposal to close 48 parks to save money, his backing of a six-lane toll road through San Onofre State Beach and his decision not to reappoint two foes of that project -- his brother-in-law Bobby Shriver and actor-director Clint Eastwood -- to the state parks commission.

Schwarzenegger, who says the power line is needed to transport clean energy, was concerned that Shriver and Eastwood might fight it too, said some officials and others familiar with the situation. The governor's aides have said he removed the pair to give others a chance to serve.

The battle highlights the tension between California's demand for infrastructure and its desire to protect natural resources.

East of San Diego in the Colorado Desert, Anza-Borrego is among the largest state parks in the United States and runs 70 miles south from Riverside County nearly to Mexico. It shelters a variety of wildlife and contains structures thought to be ancient human dwellings. Nearly a million people visit each year.

The 150-mile transmission line would run through the park for more than 20 miles, replacing wooden poles that carry lower-voltage lines with industrial-style towers up to 160 feet tall.

San Diego Gas & Electric and its parent corporation, Sempra Energy, promise that the proposed line, known as Sunrise Powerlink, would carry renewable power from the sun, wind and ground, mostly via yet-undeveloped plants in the bright, hot Imperial Valley.

State law requires utilities to supply 20% of their energy from renewable sources by 2010 -- a benchmark SDG&E has said it cannot meet. The San Diego utility supplies 6% today.

"The project's significance lies not only in its supplying additional power for a thriving and growing region but in doing so in a way that truly moves California into the future," Schwarzenegger wrote to Dian Grueneich, the California public utility commissioner overseeing the project's application, in a letter last December that came to light last month.