The Colo River flows through a wilderness area roughly 90 minutes from Sydney's CBD, entering the Hawkesbury River at a point known as Skeleton Rocks near Lower Portland. The river drains a largely undeveloped catchment, and the water quality reflects this — paddlers have described it as exceptionally clear, with clean white sand visible on the riverbed. The water runs warm in summer, with temperatures recorded around 31°C during the New Year period.

The river's character varies significantly depending on which section is paddled. The lower reach, from the Upper Colo Bridge down to Skeleton Rocks, covers approximately 23 kilometres and is current-driven with no significant rapids, making it accessible to recreational kayakers and canoeists. Because the current makes upstream return impractical, a car shuttle is necessary for this section. The upper wilderness section, from Canoe Creek to Bob Turner's Track, is a more demanding multi-day packraft or lilo trip featuring grade 2 and grade 3 rapids, including King Rapid — a significant feature that most paddlers portage due to a difficult dogleg. Below King Rapid there are two notable grade 3 rapids before the river eases into long tranquil pools.

Water levels are critical for planning. The river responds quickly to rainfall, typically peaking 24 to 36 hours after a rain event and falling rapidly. On the upper section, a gauge reading of around 1.5 metres at the put-in is considered a workable minimum, with 1.8 metres regarded as close to ideal. On the lower section, a gauge reading of 82 centimetres at Upper Colo is considered low, and at that level paddlers should expect shallow sandbars and the possibility of grounding. Quicksand has been noted as a hazard — standing in certain sandy sections can result in sinking rapidly.

Access to the lower section is via the Upper Colo Bridge (rebuilt after flood damage in 2021) for the put-in, with take-out at Skeleton Rocks. The Lower Portland ferry crossing provides an alternative route to the area. Guided kayak tours are available from the confluence of the Colo and Hawkesbury Rivers, covering 8.5 kilometres over approximately four hours, with a minimum age of 16. Canoeing, kayaking, and paddleboarding are all permitted on the river.