Yam (Mongolian: Өртөө, Örtöö, checkpoint) was a postal system or supply point route messenger system extensively used and expanded by Ögedei Khan and also used by subsequent Great Khans and Khans. Relay stations provided food, shelter and spare horses for Mongol army messengers. Ögedei Khan gave special attention to Yam because Mongol armies travelled fast, so their messengers had to be even faster, covering 200–300 kilometres (120–190 mi) per day. The system was used to speed up the process of information and intelligence.