LOS ANGELES — The long-planned but oft-delayed effort to build a high-speed rail system between San Francisco and Los Angeles has reached a major milestone with approval of the final environmental impact report on the line's stretch between Palmdale and Burbank and reports are pending Friday on other sections of the project.

The 38-mile segment was the final one between the two major cities awaiting final environmental approval.

“Today’s approval is more than a historic milestone — it closes the gap between Los Angeles and San Francisco,” Tom Richards, chairman of the California High-Speed Rail Authority Board of Directors, said in a statement following the board’s vote. “We value our Authority team and its tireless support and collaboration with local and regional agencies and stakeholders as we work together to improve transportation in California for future generations.”

Authority officials noted that the Palmdale-Burbank section will be largely underground, with four separate tunnels accounting for roughly 30 of the 38 miles. The tunnels will run beneath the Acton community and through the Angeles National Forest. Travel time between Palmdale and Burbank is expected to be about 17 minutes on the high-speed train.

Trains on the high-speed line are expected to run at more than 200 mph.

Environmental reports are still pending on the roughly 30-mile stretch of planned rail between Los Angeles and Anaheim — the final portion of the system included in what his considered “Phase 1” of the high-speed rail system. A second phase of the system would ultimately stretch from San Francisco to Sacramento on the north, and from Anaheim to San Diego on the south.

Much of the current construction work on the project is occurring in the Central Valley, where there are 25 active work sites. It was unclear when construction activities for the project will begin in Los Angeles County.