West Coasters from Fox Glacier to Haast now have access to ultra-fast broadband.
It comes as the final leg of a 250-kilometre infrastructure project to develop a more resilient telecommunications network on the coast has been completed.
Minister of Digital Economy and Communications David Clark said the rollout was extended through the Provincial Growth Fund to boost rural connectivity.
It would equip rural businesses with the tools to be more innovative and productive to support economic recovery from the Covid-19 pandemic, he said.
The West Coast was previously reliant on two fibre optic cables connecting the region through State Highway 6 and Arthur's Pass.
It left towns south of Greymouth vulnerable to telecommunications outages during severe weather events.
Clark said the government was on track to reach its goal of 87 percent of all New Zealander's having access to UFB by the end of 2022.
Since 2017, the population of West Coasters with access to UFB has increased from 23 percent to 71 percent.
Haast, one of the most remote towns on the West Coast also has a new 4G mobile tower that significantly improves mobile connectivity in the area.
It covers around 90 households and businesses as well as 14km of State Highway 6.
The nearby settlement of Hannah's Clearing will benefit too, receiving 4G coverage for mobile and broadband services and a further 4G mobile tower covering the settlements at Neil's Beach and Jacksons Bay will be commissioned later this month.
Minister of Rural Communities Damien O'Connor said it was a huge milestone that would benefit people and businesses, as improved connectivity was a key driver of economic growth.
Earlier in February, the government unveiled a major effort to upgrade capacity on rural broadband networks.
The ongoing work will see existing cell towers upgraded and new towers built in rural areas experiencing poor performance, as well as fibre, additional VDSL coverage and other wireless technology deployed in congested areas.
Chorus general manager of customer and network operations Andrew Carroll said the extended network would provide additional peace of mind during weather events on the West Coast.
"Making fibre available to residents in Haast was a uniquely Kiwi initiative; it sees residents in one of the remotest towns in New Zealand having access to one of the fastest broadband technologies available."
It also enables the Rural Connectivity Group to build 16 new mobile cell sites with robust fibre backhaul providing resilience across the West Coast.