Work has begun on the Upper Buck Gully trail project, with crews clearing the trails on the looped path that begins at Fifth and Poppy avenues.
City officials toured the site Thursday, where workers are preparing to install footings for four bridges currently under construction, said City Manager Dave Kiff.
When the bridges are complete, he said it would take minutes to install them, with a helicopter dropping them into place.
The trail, which will connect to San Joaquin Hills Road, should be complete by February, Kiff said.
The work is managed by the Irvine Ranch Conservancy, and the California Conservation Corps is doing some of the work.
The project will cost $180,000, with about half paid for by grants and the rest paid with funds from the Buck Gully erosion project.
Funds from the erosion project also will cover $185,000 to be paid for maintenance of the trail, which will be overseen by the IRC.