The percentage of native vegetation remaining in the United States is generally estimated to be less than 25%. This figure indicates that a significant portion of native ecosystems has been lost or altered due to land use changes and development. Other sources suggest natural vegetation cover around 39%, but the widely accepted assessment points towards less than one- quarter of the original native vegetation still remaining.
Thus, the best-supported estimate is that less than 25% of native vegetation remains in the U.S. today.