Because of the Platte's brackish water, the preferred camping spots were along one of the many fresh water streams draining into the Platte or the occasional fresh water spring found along the way. These preferred camping spots became sources of cholera in the epidemic years (1849–1855) as many thousands of people used the same camping spots with essentially no sewage facilities or adequate sewage treatment. One of the side effects of cholera is acute diarrhea, which helps contaminate even more water unless it is isolated and/or treated. The cause of cholera (ingesting the "Vibrio cholerae" bacterium from contaminated water) and the best treatment for cholera infections were unknown in this era. Thousands of travelers on the combined California, Oregon, and Mormon trails succumbed to cholera between 1849 and 1855. Most were buried in unmarked graves in Kansas, Nebraska and Wyoming. Although also considered part of the Mormon Trail, the grave of Rebecca Winters is one of the few marked ones left. There are many cases cited involving people who were alive and apparently healthy in the morning and dead by nightfall.