Governor George Gawler writes to Colonel Torrens, the Colonial Secretary in London about some recent explorations by Edward Eyre. In this letter he also advises that he has decided to name the mountain range to Adelaide's north and which includes Mounts Brown and Arden, after Matthew Flinders, the English navigator, who charted the South Australian coast in 1802. Flinders had named these two peaks, but not the range itself.

The rest of the letter deals with Edward Eyre's explorations and discovery. Eyre had set out from Adelaide in May 1839 to explore to the north. He discovered and named Crystal Brook, but as he progressed further north the country became drier and water more scarce. Climbing a mountain to view the country ahead, he saw only arid ranges and desert, and to the north-west salt lakes. After some exploration to the west of Spencer Gulf, Eyre returned to Adelaide by travelling along the banks of the River Murray. He would set out on another expedition in July, as Gawler mentions in his letter.