The gorge cuts through schist rock bluffs, with the vegetation on the steep slopes consisting of tussock and hardy low-growing shrubs.
Contrasting this, a ribbon of lush trees lines the immediate river banks at the bottom of the gorge.
Schist quarried from outcrops close by was trimmed and bolstered to construct the piers and abutments with the help of large gantry hoists to lift and position the stone slabs.
Both tunnels feature portals with bolstered schist slab facings, with the arches outlined in brick.
[7] Local operators in Omakau and Oturehua provide bike hire and transport, with both villages offering accommodation options as well.
After the rail trail exits the gorge, it offers good views over the Manuherikia Valley and towards the Hawkdun Range.