The idea came into focus for Stan Kroenke, the billionaire Rams owner and real estate developer, during a pre-dawn drive around Inglewood's Hollywood Park racetrack in the summer of 2013.
It grew into an audacious plan to transform 298 acres into one of the world's premier sports and entertainment districts with a $2.6-billion stadium as the centerpiece.
On Thursday, Kroenke stepped out of a black SUV on the site bustling with massive earth-moving equipment and the project took a ceremonial step forward.
With more than 100 invited guests in attendance — politicians, media, members of the Pro Football Hall of Fame and even NFL Commissioner Roger Goodell — Kroenke and others plunged shiny silver shovels into a pile of dirt and extolled the virtues of a privately financed stadium that's expected to cost more than any other.
"This thing is going to be unbelievable," Kroenke said. "I don't think people really understand the scale of this."
On a piece of land that's 3½ times the size of Disneyland, the stadium will be surrounded by a development that includes a performance venue, hotel, hundreds of thousands of square feet for retail and offices, homes and a lake with waterfalls.
"We had to get it right and this is getting right," Goodell said of the NFL's return to Los Angeles after a two-decade absence.
The 70,240-seat stadium — able to accommodate 25,000 extra people in standing-room areas behind the end zones — is scheduled to open for the 2019 NFL season and will host the Super Bowl in 2021.
Rams officials already have been in talks with the NCAA about hosting future Final Fours, in addition to discussions about being a site for a College Football Playoff championship game and playing a role in the LA 2024 Olympic bid.
Much of the low-slung, waved-shaped stadium will be covered by a transparent roof, but the building will remain open on the sides. The building will be set 80 to 90 feet into the ground — 10 feet shallower than originally planned — with approximately 175 feet above ground.
"For the first time, we have a true indoor/outdoor venue. … It's totally unique in the world," said Mark Williams, who heads the sports and entertainment division at stadium architect HKS.
While infrastructure work has been underway for more than a year and a half, the start of excavation this week is the latest sign of progress on the project. The process is expected to take six to eight months.
The City of Inglewood approved grading and excavation permits for the project in recent weeks.
The Federal Aviation Administration has been reviewing the stadium's design for more than a year because of concerns that the structure would conflict with radar at nearby L.A. International Airport.
"We have worked with the FAA on potential solutions both from a materials perspective and potential solutions that don't impact the design of the building," said Kevin Demoff, the Rams' chief operating officer.
"We've had really productive conversations with them throughout the year. I think we're making good progress, but there's always work to do to make sure that we get a building that they're very happy with."
The FAA has declined to comment on the status of negotiations, though an agency spokesman said it is pausing approval of six large cranes for the project until the design issue is settled.
There haven't been significant changes in the latest renderings of the stadium from the images presented to NFL owners in January. In a 30-2 vote, they chose the Inglewood project over a competing concept in Carson backed by the San Diego Chargers and Oakland Raiders.
Demoff said that Kroenke "wants to make sure that this building is everything that he stood up in front of the NFL owners and said it would be."