[2] Its two source rivers Schwarze and Weiße Sulm [ceb; de; sv] both originate at the eastern slopes of the Koralpe (a north-south running mountain range in the Southeastern Alps which separates Styria from Carinthia).

A unique geographic feature in the Sulm valley is the Sausal mountain range which has its own mild microclimate, supporting a significant fraction of Styria's wine-growing economy.

Apparently a halidom for female goddesses throughout the Neolithic and Celtic periods, its plateau bore a temple during Roman times when the municipium of Flavia Solva flourished.

Many settlements in the lower Sulm valley likely date back to the 9th century when the Bavarians reclaimed the region from the predecessors of the current Slovenes who had loosely settled it after the rule of the Avars had succumbed to Charlemagne.

In 1532 Turkish troops retreating from their abortive first Siege of Vienna moved southward along the Mur, and laid waste to a broad swath of land on both sides of the river; their cavalry pillaged, burned and abducted almost unhindered.

[3] The Sulm valley region lost many vital connections to the South (especially to the city of Marburg an der Drau, now Maribor) in 1919 when Lower Styria was annexed to emerging Yugoslavia.

Those parts of the groundworks that had not been removed during the following decades have now mostly been converted to a biotope, providing shelter for the local fauna and flora and offering a distant reflection of what the Sulm valley bottom had been before it was diverted to the present intense agricultural use.

The soil of the Sulm valley is rich, and its economy is characterized by agriculture (mostly maize, but recently also alternative crops) and - on the hillsides and in the Sausal mountain range - also wine.

In earlier times, when peasants went barefoot except on Sundays or special occasions, the clay sticking to their feet made them yellowish-brown and therefore they were nicknamed Gelbfüße ("yellow-feet").