The Solar water disinfection (SODIS) technique, which utilizes both solar heat and ultraviolet radiation to kill microorganisms, is included in wilderness medicine texts and practice guidelines as a viable option for disinfecting emergency drinking water. While this method has been studied using polyethylene terephthalate (PET) plastic water bottles on tin roofs, it has not been examined using water containers usually available to the backcountry traveler, in typical wilderness conditions. The aim of this pilot study was to assess the feasibility of using materials and equipment typically available to the outdoor enthusiast to carry out the SODIS technique to disinfect drinking water. On a wildlife preserve, near Dominical, Costa Rica, fresh stream water from a single site was sampled into various containers, including: Nalgene 32oz wide mouth clear bottles, Platypus 2L flexible water bottles, and standard PET water bottles. The published SODIS technique was followed: partial filling of the bottle with relatively clear water, aeration through shaking, and then further filling of the bottle. Treatment bottles were exposed to bright sunlight on a backpacker's reflective survival tarp for six hours. Control bottles were exposed to a cool, dark room (CDR) during the same time period. Pre- and post-exposure samples were plated on 3M Petrifilm E. coli/Coliform Count Plates and incubated in accordance with manufacturer specifications. Colony-forming units were photographed with a digital camera after 24 hours of incubation and counted. This entire protocol was then repeated for a second sampling day. For day one sampled water, placed in CDR exposure bottles, the following log reductions in E. coli colonies and coliform colonies were noted, respectively: Nalgene (0.08; 0.05), PET (0.12; 0.08), Platypus (0.04; 0.03). Day one SODIS exposure bottles showed the following log reductions, respectively: Nalgene (2.16; 2.41), PET (2.31; 2.57), Platypus (2.18; 2.40). For day two sampled water, placed in CDR exposure bottles, the following log reductions in E. coli colonies and coliform colonies were noted, respectively: Nalgene (0.18; 0.03), PET (0.07; 0.21), Platypus (0.48; 0.25). Day two SODIS exposure bottles showed the following log reductions, respectively: Nalgene (1.62; 2.27), PET (1.50; 2.50), Platypus (1.08; 1.90). With the use of backcountry equipment, the SODIS technique demonstrated reduction in E. Coli and coliform counts in both Nalgene and Platypus bottles, in addition to the recommended PET bottles. Bacterial counts were reduced to negligible levels in all bottle types. While this pilot study was not large enough to achieve the common standard of a three to five log reduction in microorganisms, post-treatment water had a significant decrease in total coliform count, and in almost all cases, no detectable coliform bacteria in the post-treatment samples. A more comprehensive study of the SODIS technique, with equipment typically available in a backcountry setting, is needed to demonstrate the effectiveness of the technique. This method of water purification is simple, inexpensive, and has the potential for significant implications for health and safety in austere environments.