||During rapid-onset disasters, timely dissemination of warning information to the public is crucial. Official emergency information channels are often slow, leaving the public to monitor social media websites for more timely updates. Examining Twitter communications, or tweets, sent during the 2012 Waldo Canyon Fire, this research seeks to determine what level of descriptive information is sent through Twitter during a wildfire, whether or not that information can inform other users of changes in fire activity, and how the spatial and temporal information within a tweet can be used in conjunction with geographic information systems (GIS) to determine fire location and activity. This research utilized geotagged tweets and viewshed analysis in GIS as a means of determining what portions of the wildfire are visible from each Twitter user. These visible areas, or viewsheds, were then overlapped with viewsheds from other users to generate shared viewsheds. Both individual and shared viewsheds were compared to the area of new fire growth to determine if burning areas could be more confidently identified by considering different user perspectives. The shared viewshed method showed that while increasing the number of observations does result in a decrease in shared visible area, the portion of the shared viewshed that falls within the fire boundary significantly increases. Many groupings, iv which were compiled based on time sent and ranged in size from two to eight tweets, could see more than 20% of the fire. This research found that there is the potential for users to inform one another of changes in fire activity that may not be visible from different points of view. The addition of viewshed analysis adds another layer of valuable information to the tweets and could be useful if done in real-time, especially during events occurring at a smaller scale.