In 1973 pairt o the destrict Müllheim an sma pairts o the destrict Säckingen wur addit tae the destrict, which enlairgit the destrict bi aboot 25% tae the current size.
The north-east o the destrict is pairt o the Hochschwarzwald, the heichest pairt o the Black Forest. In the wast is the Markgräfler Hügelland, in the sooth the Dinkelberg, baith lawer hilly auries. The Rhine river, which forms maist o the destrict's soothren an wastren border, is in a narrae valley till it spreads north o Basel in the hintle wider Oberrheinebene.
The coat o airms o the Lörrach destrict can be blazoned as Per fess Argent a Demi Lion facin sinister Gules an in base per pale Or a Bend Gules an Azure a Bend Sinister wavy Argent. The lion in the top pairt o the coat o airms represents the Lairds o Rötteln, who had their primary castle in Loerrach, Wiesental. The bottom-left shows the coat o Baden, as hintle o the district belangit tae the Coonts o Baden historically. The wavy line in the bottom-richt represents the sma river Wiese, which flows through the destrict.