Hann's explorations covered a great deal of the state while searching for mineral wealth and pastoral prospects. From 1903 he based himself in a tent about 10 kilometres east of Laverton. His expeditions from the locality (shown as "Hann's Camp" on modern maps), extended as far as the Petermann Ranges in central Australia and Oodnadatta in South Australia. He left a legacy having named over 500 geographical features, including the rivers Rudall, Isdell, Charnley and Phillips (now the Hann); lakes Yeo and Rason; and ranges Mackay, Sir Frederick Bedford and McFadden Range.