Cooper Creek is a river in east central Australia, which was explored in the mid-1840s by Charles Stuart and Sir Thomas Livingston Mitchell. The stream flows intermittently for about 1,420 kilometres (880 miles) through the Channel Country. Its drainage area is around 296,000 square kilometres (114,000 square miles) of cattle pastureland. It rises as the Barcoo in the Warrego mountain range, then flows northeast to Blackall, after which it assumes a southwesterly course. It then receives the Thomson, its biggest tributary, and is sometimes known as Cooper Creek from this point onwards. During times of very high rainfall it will carry water all the way to Lake Eyre.