The Los Angeles County Museum of Art continues to move forward with plans for a $600-million makeover of its Miracle Mile campus, with the project's environmental review process now underway.

A draft environmental impact report now being circulated by the County offers up new details on the project, which is highlighted by a 390,000-square-foot building that would span across Wilshire Boulevard. The new construction, which is being designed by the architect Peter Zumthor, would replace LACMA's Bing Center and Hammer, Ahmanson, and Art of the Americas BUildings.

The project is more redesign than expansion, and will ultimately decrease its square footage by approximately 5,000 square feet. Nonetheless, plans call for the addition of a new dedicated parking garage at the corner of Wilshire and Ogden Drive, with space for up to 260 vehicles.

Zumthor's design calls for "seven semi-transparent structures" at the property's ground level, which are referred to as Pavilions. The Pavilions would support the elevated main exhibition level, extending south across Wilshire Boulevard to a property along Spaulding Avenue. Raising the museum's footprint off of the ground level frees up approximately 2.5 acres of the campus for public open space, with plans calling for landscaped plazas, educational spaces, sculpture gardens and native vegetation.

The design has evolved since the project was first announced in 2014. Originally envisioned as a more amorphous structure located along the north side of Wilshire, the project was tweaked to span across the boulevard due to concerns that the construction would adversely affect the adjacent La Brea Tar Pits. An updated design composed of sand-colored concrete was unveiled earlier this year.

The environmental report also studies two alternate development plans: a museum building solely north of Wilshire without a street crossing, or two separate buildings located on opposite sides of Wilshire.

Construction of the new building is expected to begin in late 2018, with completion tentatively scheduled in 2023.

As of this month, LACMA has raised $450 million of the total $600 million project budget, bolstered by a $150-million donation by David Geffen.

Another ambitious project is already underway on the west side of the LACMA campus: the Academy of Motion Picture Arts and Sciences' $388-million museum.