In the summer of 2013 public health officials in Oregon investigated an outbreak of Cryptosporidiosis in Baker County, Oregon. A total of 119 cases (23 confirmed and 96 presumptive) were identified. Two people were hospitalized. Cases experienced symptoms in July and August 2013.

Water samples obtained on July 31 and August 4, 2013 from multiple watershed intakes and from within Baker City tested positive for Cryptosporidium oocysts. A high-volume water sample collected at the end of the municipal water line in Baker City on July 31 tested positive for Cyptosporidium at the CDC. The means of contamination of the Baker City water supply was not determined although contamination of the watershed by cattle was considered to be most probable.