Answer the following Q with stream of consciousness. Passage: An oxbow lake is a U-shaped lake that forms when a wide meander from the main stem of a river is cut off, creating a free-standing body of water. This landform is so named for its distinctive curved shape, resembling the bow pin of an oxbow. In Australia, an oxbow lake is known as a billabong, from the indigenous Wiradjuri language. In south Texas, oxbows left by the Rio Grande are called resacas.'

Question: Based on this passage, in which course of the river are oxbow lakes formed?

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
To answer the above question, the relevant sentence is: An oxbow lake is a U-shaped lake that forms when a wide meander from the main stem of a river is cut off, creating a free-standing body of water. Therefore, the final answer is when a wide meander from the main stem of a river is cut off , creating a free - standing body of water.