kadina wallaroo as NG and was convert to BG however when the SG between Adelaide and Port pirie opened an put a third rail down to make the both SG and BG. Now the line is only BG gauge as YPR convert to BG most of the SG is still there however there are parts missing.
There was a broad gauge horse tramway for 15 years before the SAR narrow gauge line arrived in 1877.
David is correct. Rail transport between those two towns went from BG horse tram to NG steam train to BG steam (and later diesel) trains. The line to Moonta was closed before the SG reached Wallaroo.
Your question David.