The rapid, creek and camp are named after Peter Mallard, a miner, and not the duck.
If you plan on scouting this rapid, do so from the left bank after you go around the corner.
The predominant feature of Big Mallard is an enormous boulder located towards the bottom of the rapid, which creates a large hole. Just to the left of the hole is enough space for a raft to fit through. The general line is to stay left the entire time and then to shoot through the gap between the left bank and the Big Mallard hole. Your reading water intuition will try to convince you to run right, as far away as possible from the hole, but the water is deceiving and pushes back towards the inside of the corner directly towards the feature.
In the screenshot above you can see why a right line is not a good idea. Despite the river making a left turn, the water pushes you back inside directly towards the hole. The red dotted line shows the easier, normal route. It looks like there’s no space, but when you’re in there, you’ll have plenty of room.