Mining remains one of the most hazardous industries in the United States, and miners continue to face risks associated with machinery operation, ground instability, confined environments, and high energy sources. In this study, we examine long term trends in accident and injury outcomes in United States surface and underground mines from 2000 to 2023 using publicly available Mine Safety and Health Administration surveillance data. We use a retrospective longitudinal design and integrate information from the Accident, Injury, and Illness database and the Employment and Production dataset. We calculate all standardized indicators per two hundred thousand employee hours. We summarize exposure patterns and accident characteristics with descriptive statistics and evaluate temporal patterns using regression models. Our results show substantial declines in accident frequency and severity rates in both surface and underground mines. However, underground operations maintain higher rates and display greater year to year variability. We also find that fatality rates decrease over time but remain consistently higher in underground environments. Accident type distributions reveal that machinery, slips and falls, and handling materials incidents dominate surface mines, while fall of ground and powered haulage hazards remain concentrated in underground operations. Injury severity classifications show a clear shift from fatal and lost time injuries toward lower severity medical treatment cases. These findings demonstrate measurable improvements in national mining safety performance and identify persistent high risk conditions that require targeted prevention.