Temporary fences are being erected around bush in Upper Hutt, after a truck crash let loose 19 cattle.
The truck crashed on Blue Mountains Rd and the attached trailer fell over the edge.
The two vehicles have now been separated and the road re-opened, however the trailer will remain in place until a crane can remove it on Wednesday morning.
Nineteen cattle escaped the trailer after the crash and some remain wandering in the bush.
Police say they shouldn't pose a threat to the public as they are "quite timid and de-horned".
A local farmer will return for the cattle on Wednesday morning but until then, the fences will remain in place.
The state of the driver is not yet known.