This paper presents the results of contractor worker personal exposure monitoring from 3,663 samples and construction management (CM) worker monitoring from 1,292 samples collected during the 7-year Calaveras Dam Replacement Project. The samples were analyzed using NIOSH M7400 and adjusted using NIOSH M7402. The contractor monitored workers who were involved in the disturbance activities, such as laborers, drillers, bulldozers, and excavators, whereas the CM team monitored workers such as geologists, engineers, and biologists. The data set was analyzed by work categories and lithologic units (chrysotile from serpentinite and amphiboles from blueschist). The CM team data set was also differentiated by amphibole species, providing sets by two metrics: chrysotile plus all amphiboles included, and chrysotile plus the five “regulated” amphiboles only. Exposure by amphiboles to the contractor's workers were highly elevated, with the daily maximum ranging from 0.129 f/cc to 1.813 f/cc, and means ranging from 0.042 f/cc to 0.106 f/cc. The highest exposures were associated with the laborers and the drillers working within blueschist. Lower exposure concentrations were reported for serpentinite, with mean exposure concentrations ranging from 0.01 f/cc to 0.024 f/cc. The amphibole exposures (62% likelihood of permissible exposure limit [PEL] exceedance) were higher than chrysotile (3% likelihood of PEL exceedance) largely because the hard-rock blueschist could not be thoroughly wetted. Exposures to the CM team members were significantly lower: the mean exposure concentrations ranged from 0.0049 f/cc to 0.0085 f/cc (all-amphibole metric) and from 0.0002 f/cc to 0.0048 (“regulated” amphibole metric). CM workers did not work on the site all day, which depressed their exposures when reported as an 8-h time weight average. Exposures ranged from 0.0037 f/cc to 0.0069 f/cc (all-amphibole metric), and 0.0001 f/cc to 0.0034 (“regulated” amphibole metric). The data show that reporting only the Occupational Safety and Health Administration–regulated amphiboles would have resulted in an underestimation of exposure by 98%.