Australian bass are found at their highest altitude in the freshwater reaches of rivers during the months of December, January and February. Research indicates there is sexual segregation in this non-spawning season for resource partitioning purposes. Males inhabit the lower freshwater reaches of rivers while females travel far into the middle and even upper freshwater (upland) reaches. The distance Australia bass travel upstream appears to be limited only by flows and impassable barriers (historically, waterfalls; today, often, dams). Thus, historically, the effective altitudinal limit for Australian bass has been as high as 400–600 metres in some river systems. For instance, Australian bass originally migrated up to the Dalgety region in the Snowy River, well above Oallen Crossing on the Shoalhaven River and far up the Warragamba River and Coxs River before these rivers were dammed: