Students living in rural areas are less likely to attend schools that offer computer science (CS) courses largely because educational institutions in these remote areas lack the resources to staff teaching positions for these courses. This study investigated the impact of WeTeach_CS, a program designed to train teachers to become certified to teach high school CS in Texas. This research project examines the effectiveness of the WeTeach_CS collective impact model for increasing the number of certified CS teachers in rural schools. Interrupted times series (ITS) analysis was used to investigate the impact of the WeTeach_CS program on the number of certified computer science teachers in rural schools. The authors hypothesized that the WeTeach_CS program would positively impact the number of certified CS teachers in rural schools but that this effect would happen gradually over time. The results of this study demonstrate that large-scale collective impact interventions can be effective in increasing the number of certified CS teachers. Moreover, given the statistically significant change in slope between the pre-intervention and intervention phases, this study shows that program effects can be sustained over time.