Researchers from the University of Nevada, Reno, say the entire mountain range is being elevated at a rate of 1 to 2 millimeters every year.
The rate, though seeming miniscule, suggests the modern Sierra could have formed in less than 3 million years, they said.
The scientists used satellite-based GPS data and space-based radar data to calculate the movements with unprecedented accuracy, a university release reported Thursday.
"The exciting thing is we can watch the range growing in real time," lead researcher Bill Hammond said of the multiyear project to track the rising range, said.
"Using data back to before 2000 we can see it with accuracy better than 1 millimeter per year. Perhaps even more amazing is that these miniscule changes are measured using satellites in space."
The findings may help resolve debate regarding the age of the modern Sierra Nevada of California and Nevada.
The history of the range's elevation is complex, researchers said, exhibiting features of both ancient (40 million years) and relatively young (less than 3 million years) elevation.
The "young" elevation is the uplift Hammond and colleagues said they have tracked.