Hirere Falls is the first major named waterfall you'll probably encounter on the Milford Track. You can start to see this waterfall behind Dead Lake as you tramp through the Clinton Valley. You can get more direct views of this waterfall from the similarly-named lunch shelter. Now all this assumes that you can pick out this waterfall from the zillions of other waterfalls you might see in Clinton Valley.
For more information on this waterfall such as...
maps
directions
detailed descriptions
refer to A Guide to New Zealand Waterfalls (Story Nature Press).