Mackay Falls is an interesting wishbone-shaped waterfall on the Milford Track. While lacking in height and power, it is a welcome sight after going for a long stretch without seeing a major named waterfall in Arthur Valley (Sutherland Falls was probably the last one you saw until now). Also check out the interesting Bell Rock, which is next to the wooden platform for the waterfall.
For more information on this waterfall such as...
maps
directions
detailed descriptions
refer to A Guide to New Zealand Waterfalls (Story Nature Press).