His first job in the natural sciences was working for William W. Price as a scientific collector in Mexico from 1896 to 1897. He was joined by his brother, Luther. The mammal specimens collected on this 10-month expedition were purchased by the British Museum. British Museum zoologist Oldfield Thomas was so pleased by the quality of the specimens, he offered Simons a job collecting additional specimens in South America. Luther accompanied Perry for the first two years of the expedition before sailing back to San Francisco.[1]
Death
While crossing the Argentinean Andes around the end of December 1901,[1] Simons was murdered by his guide.[2] The guide struck him in the back of the head before driving a spike through his forehead. His body was found, and it was buried nearby. The motive was said to be robbery, and the guide was captured and imprisoned in Mendoza, Argentina.[1] After Simons's death, Oldfield Thomas called him "the most successful mammal collector that I have ever had to deal with", noting, "we shall not easily find his like again".[3]