The Mô river runs through the northern part of the park, fringed by a strip of denser, taller forest that survives because the water table sits close to the surface year-round. This kind of gallery forest is the richest habitat in Fazao — most of the larger mammals visit it daily, primates favour the canopy, and the deep shade makes it a pleasant place to walk even at midday.
A footpath from the park's main track follows the river for several kilometres past pools where hippos sometimes appear (cautiously — keep ranger guidance), and stretches of pebble bank where buffalo and bushbuck tracks tell the previous night's story. The river is at its most reliable in the late dry season, when it pools rather than flows; in the wet months it can swell quickly.