The Arrowsmith Thee Races in Canterbury, New Zealand has several running and mountain bike events, and a MTB / trail run duathlon.
The trail runs are the Arrowsmith High Country 42km Marathon, Lake Face 17km Trail Run, and 10/11km Fun Run. The MTB event is 42km mountain bike option covering the same course, and the duathlon is the 42km MTB course, followed by the 10/11km run course.
The course heads up the Cameron River nearly to the source, up and over a saddle into the South Ashburton River then a blast down the river bed over another small saddle and then back across the paddocks to the woolshed.
42K, 17K & 10/11K Trail Run/Walk
42K MTB + 10/11K Trail Run/Walk