Map shewing the route of the West Australian Exploring Expedition through the centre of Australia from Champion Bay on the West Coast to the Overland Telegraph Line between Adelaide and Port Darwin commanded by John Forrest, F.R.G.S. 1874 State Library of Western Australia (Call No: 24/8/1) available online:

This image shows the routes of the three exploring expeditions of John Forrest. It is taken from Forrest’s account of his journeys, [ Explorations in Australia]
Diagram shewing triangulation between Champion Bay & the Weld Range. State Library of Western Australia (24/3/1)

Google Map route of John Forrest’s 1874 expedition