Wildland fire behavior models are often initiated using the detection information listed in incident reports. This information carries an unknown amount of uncertainty, though it is often the most readily available ignition data. To determine the extent to which the use of detection information affects wildland fire forecasts, this research examines the range of burned area values and propagation directions resulting from different initiation point locations and times. We examined the forecasts for ten Colorado 2018 wildland fire case studies, each initiated from a set of 17 different point locations, and three different starting times (a total of 520 case study simulations). The results show that the range of forecast burned area and propagation direction values is strongly affected by the location of the initiation location, and to a lesser degree by the time of initiation.Published version