Because the Routeburn Track is one of New Zealand's Great Walks, you have to book your accommodation well in advance and the itinerary is pretty inflexible. Most people take three days to do the Routeburn, leaving a short last day onto which it's easy to tack the Greenstone Track. I rushed round the Greenstone a little because I'd had enough of lush river valleys by then, but if you have the time I'd recommend taking an extra day and splitting the journey between Lake Howden and Sly Burn at the McKellar Hut.
|Routeburn Track||1||Routeburn Shelter to Routeburn Flats||6.5|
|2||Routeburn Flats to Mackenzie Camp||13.6|
|3||Mackenzie Camp to Lake Howden||8.6|
|Greenstone Track||Lake Howden to Sly Burn||26*|
|4||Sly Burn to Greenstone Car Park||11*|
Please note that distances marked with an asterisk are estimates. The Greenstone Track is 37km long, but I don't currently have the maps to hand to check the figures for the individual days.