The Gearhameen River is a whitewater kayaking run in Co. Kerry, graded at 3-4, located deep in the Black Valley beyond the Gap of Dunloe. The river flows within Killarney National Park and ultimately enters the western end of the Upper Lake, Killarney. It sits within the Killarney National Park, Macgillycuddy's Reeks and Caragh River catchment SAC, a designated Special Area of Conservation.

To reach the put-in, drive past Kate Kearney's Cottage and through the Gap of Dunloe. After the road begins to descend on the far side of the gap, take the first right (marked as a cul-de-sac), then the first left. The put-in is at a small bridge. The take-out is the next bridge downstream; from the cul-de-sac junction, continue straight to reach it. There is parking on the right after crossing that bridge. Put-in coordinates are approximately 51.9772°N, 9.6765°W, and take-out coordinates are approximately 51.9809°N, 9.6388°W.

Water levels significantly affect the character of the run. At low water, paddlers can pass under the bridge at the put-in; at medium water, rolling under the bridge is required; at high water, the bridge is flooded and extra caution is needed. High water also increases the speed of the river and may push the grade higher.

The most significant hazard on the run is a slot drop with major pinning potential. This feature has produced pinning situations on multiple occasions and demands careful attention. Numerous trees along the river add to the hazard profile and require vigilance throughout the descent.

No access issues are noted for this run.