Illegal mining is very common around the world: 67% of United States companies could not identify the origin of the minerals used in their supply chain (GAO, 2016). Currently, National Governments around the world are not able to detect illegal activity, losing valuable resources for development. Meanwhile, the pollution generated by illegal mines seriously affects surrounding populations. We use Sentinel 1 and Sentinel 2 imagery and machine learning to identify mining activity. Through the user-friendly interface called Colombian Mining Monitoring (CoMiMo), we alert government authorities, NGOs, and concerned citizens about possible mining activity. They can verify if the model is correct using high-resolution imagery and take action if needed.