Mormon Pioneer Mortality Rates Calculated At 3.5 Percent (image) Brigham Young University Share Print E-Mail Caption This is a group of group of Mormon pioneers at South Pass, Wyoming, circa 1859. Photo by Charles Roscoe Savage. Credit Charles Roscoe Savage Usage Restrictions For use with coverage of the pioneer mortality study Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.