The Owenglin flows from a valley in the Twelve Bens mountain range through the town of Clifden in Connemara, County Galway, where it meets the sea at Clifden Bay. The upper river section spans over 9 kilometres and is divided into three distinct segments — the Forest section, the Upper section, and Simon's Falls — allowing trips ranging from a full 9km paddle to a shorter park-and-paddle session at Simon's Falls. The river is graded 3 to 5 overall.

The Upper section begins at the upper bridge with predominantly grade 2 water winding through open countryside. After approximately 1 kilometre the gradient increases, producing several grade 2/3 rapids. A notable feature is "Hot as Balls Falls," a grade 3+ drop of roughly 15 feet into a canyon with a large pool below. Both left and right lines are considered worthwhile, though a hole on river-right can slow momentum and may become more problematic at higher water levels. Scouting and safety setup are recommended here. The river continues with grade 2/3 rapids to the take-out at the bridge.

Trojan Falls carries a lethal risk and demands adequate safety arrangements. The Forestry section and the area below Simon's Falls can contain wire and other debris blocking the river. Below Simon's Falls, before the take-out, a protruding iron bar presents a hazard at certain water levels. The length of the run means paddlers should allow sufficient time to complete the trip in daylight.

The Owenglin is a popular fishing river, and paddlers are asked to avoid it during fishing season. When anglers are actively fishing pools, the practice is to portage that rapid or drop rather than paddle through.

The lower river passes through Clifden, the largest town in Connemara, before entering Clifden Bay over falls described as picturesque. The canyon setting around Hot as Balls Falls is noted as a particularly striking stretch of the river.