The Los Angeles County Board of Supervisors voted 5-0 Tuesday to certify the environmental documents and signaled their intent to approve Landmark Village, the first phase of Newhall Land Development’s Newhall Ranch “mini-city” west of Interstate 5.

County Regional Planning staff will prepare the findings from Tuesday’s public hearing and present them to the board for final approval “hopefully before the end of the year,” Planner Samuel Dea said.

The 263-acre Landmark Village is the first of five phases of the eventual 20,660-home Newhall Ranch development, which received conceptual approval from the county in 2003. It is estimated that when all five phases are complete, Newhall Ranch will add about 70,000 new residents to the Santa Clarita Valley.

Landmark Village is to be a 1,444-home community south of Highway 126 and northwest of Six Flags Magic Mountain. It would consist of 733 condominiums and apartment units, 270 single-family homes and 1.03 million square feet of commercial and retail space.

The Regional Planning Commission approved the phase in early 2008, but it was held up when the U.S. Army Corps of Engineers raised concerns about encroachment on the Santa Clara River where endangered plants and animals live.

The biggest difference between the version approved by the Regional Planning Commission and the version supervisors saw Tuesday was an additional setback from the river, Dea said last week.

The supervisors will take a second look at Newhall Ranch later this month when they consider the considerably bigger Phase 2.

That phase, called Mission Village, is envisioned as a 1,262-acre, 4,055-home community bounded by Westridge on the south, Magic Mountain on the east, and Highway 126 on the north and west. It would consist of 3,704 multi-family units, 351 single-family homes, 1.56 million square feet of commercial space, an elementary school, library, fire station and bus transfer station.

Together, phases 1 and 2 call for the removal of 210 oak trees including 18 heritage oaks, Dea said. However, they also set aside 693 acres for open space and three habitats for the endangered spineflower.