From the official parking take the Red and Yellow trails (in reverse) along the forestry road and follow this road and it will lead you to the Anderson Dam turnoff, which is signposted at Anderson Dam Walk #8.
Please note the accuracy of the coordinates is affected by the heavy tree cover. Use the hint and your geocaching skills and then it should be a relatively easy find as the cache is placed just off the road in the forest.
There are many more caches along the Red and Yellow trails, as well as the Blue trail (in the opposite direction) leading to the three waterfalls in this beautiful Kologha Forest.