River_Shimanto_Ultramarathon
The River Shimanto Ultramarathon, also referred to as Shimantogawa Ultra Marathon (四万十川ウルトラマラソン), is a 100 km and 60 km ultramarathon foot road race event held annually in October in Kochi, Japan since 1995.[1][2][3] It is an official 100 km and 60 km event endorsed by JAAF.[4][5] Its 1998 event was held as IAU 100 km World Championship.[6][7] Time limit for the 100 km race is 14 hours, and that for the 60 km race is 9 hours and 30 minutes.[8]