The project recently received environmental review approval from the Federal Railroad Administration, allowing the plan to move forward.
Construction is expected to cost $12 billion.
San Bernardino County received $25 million from the federal government for the project.
That money will be used on the high-speed rail stations in Hesperia and Apple Valley.
The Brightline train will also make stops near Rancho Cucamonga and the Las Vegas Strip.
The company says its high-speed train will have zero-emissions and will take half the time it takes to drive from Los Angeles to Las Vegas.
Groundbreaking on the rail system could start later this year.