This track leads from Whakahoro up the Kaiwhakauka Valley past the Mangapurua Trig and then descends through the Mangapurua Valley to meet the Whanganui River at the Mangapurua Landing, 30 km upstream from Pipiriki. At the lower end of the valley the track crosses to the true right bank of the stream over the historic "Bridge to Nowhere". This is a large concrete bridge built in 1936, but is now standing abandoned in the bush in the middle of "Nowhere".
However we recommend doing it in the reverse direction and getting the jet boat to Mangapurua Landing, that way you don't have any time constraints with pickups.
Doc Track Info: track info
Tramper website track info: http://tramper.co.nz/?4849