Greenstone Valley and Hollyford Valley were one of the easier access roads from Central Otago to western coast. Paths through these valley were already discovered by first inhabitants Waitaha. As at another parts of New Zealand people wandered and searched for Pounamu (green stone). Pounamu was much accounted as material for tools, weapons and ornaments. First white men came in 1862. Greenstone and Caples trails meets at David McKellar lake. The lake bears a name of explorer who discovered it. These two trails is possible to combine with Routeburn trail. The last one belongs among Great Walks.
Patrick Caples explored the area in 1863. To get to western coast I used trail with his name. Both valleys has been used for pasturage since 1880. Trails lead along rivers, on pasture or through deep beech forests. Caples trail is compared to Greenstone trail more demanding. You have to more times cross the river what can be complicated after heavy rains. West of Mc.Kellar gap (the highest point has over 900m) is very steep slope and trail leads over many roots. Although all this crimps this Caple trail is nicer.
There are several cabins along both trails . You can camp alongside forest and at last 50 meters from the trail. As pasture are private it is prohibit to camp on them.