 Following the failure of the Denison Plains scheme, Wedge was employed at Roebourne as a Western Australian government surveyor.Among other projects, in 1866 the Government Resident, Robert John Sholl tasked Wedge with finding a suitable harbour in the Port Hedland area, to encourage and service settlement further north, in areas such as the De Grey River.The natural harbour of Port Hedland itself was already considered unsuitable, due to the thick mangroves.