NORTH COUNTY -- A 120-mile string of proposed high-power electrical transmission lines would cut through the backcountry communities of Ramona, Santa Ysabel, Poway and Rancho Penasquitos, power officials said Monday morning after weeks of debate and protest over the project.

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San Diego Gas & Electric officials said the high-voltage lines would run straight through the Anza-Borrego Desert -- California's largest state park -- skirt around Julian and cut through North County to hook up with the Penasquitos power substation.

Officials said that the power lines would be laid underground for five miles in Ramona and two miles in Rancho Penasquitos to lessen their visual intrusion in those communities, but would be erected on 130-foot to 160-foot tall metal towers for the other 113 miles.

Utility officials unveiled their preferred route this morning at a meeting in Rancho Penasquitos. A public town hall meeting to discuss the route is planned for 4 p.m this afternoon at the Ramona Performing Arts Center, 1521 Hanson Lane.

SDG&E officials said they would try not to place the proposed power lines directly overhead of any houses.

SDG&E is seeking the green light from the California Public Utilities Commission for the transmission line.

If the plan is approved, the power line would begin in Imperial County and cut a winding path through North County to Rancho Penasquitos.

The proposed transmission line has sparked much concern among critics and environmentalists, who have said the wires will slice through the backcountry.

The utility says the line would deliver 1,000 megawatts, roughly one-fourth of the total its customers collectively use on the hottest of summer days. A megawatt is the standard measuring unit for electricity, and typically is enough to keep the lights on in 750 to 1,000 homes, according to the California Independent System Operator, which oversees the state's electric grid.

SDG&E says it wants to build the electron superhighway to shore up a looming shortfall of electricity in San Diego County and to tap developing sources of geothermal and solar power near the Salton Sea in Imperial County.

Geothermal technology uses steam from natural underground geysers to produce electricity, and solar panels harness the sun's raw power. The surge of interest in solar, geothermal and other energy sources is being driven by a state law that requires California utilities to obtain 20 percent of their electricity from so-called renewable sources by 2010. SDG&E gets 6 percent from such sources now.

But conservationists contend there are other ways to boost the region's power supply, and that those alternatives must be explored because of the deep wound -- as wide as a football field -- that the line would cut into oak-covered mountains and wildflower-carpeted desert canyons.

Staff writers DAVE DOWNEY and GIG CONAUGHTON contributed to this story.