Places We Protect

Wainiha Valley

Island of Kauaʻi

Located at the head of Wainiha Valley, Kauai, Hawaii.
Hinalele Falls Located at the head of Wainiha Valley, Kauai, Hawaii. © Ethan Welty

Hawai‘i’s third largest private nature preserve is spectacular Wainiha Valley on Kaua‘i.



As the state's third largest private nature preserve, the 7,050-acre Wainiha Preserve includes one of Kauai's largest river systems, magnificent mountain cliffs, and portions of the famed Alaka'i wilderness and Mt. Wai'ale'ale summit region, one of the wettest spots on Earth.  


Wainiha is home to 127 species of flowering plants found only in Hawai'i, 41 of which are found only on Kaua'i. Alaka'i Summit Plateau contains 131 flowering plant species found only in Hawai'i, 46 of which are found only on Kaua'i.

Species of interest include:

  • Laua'e fern: Upper Wainiha Valley contains one of the largest populations of the rare Microsorum spectrum, the famous fragrant laua'e fern of Kaua'i chant and traditions
  • Cyrtandra cyaneoides (endangered)
  • Plantago princeps var. logibracteata
  • Phyllostegia helleri, a native mint

A native mint previously thought to be extinct in the wild, Phyllostegia helleri was rediscovered in Wainiha Valley in 2004 by Ken Wood (National Tropical Botanical Garden) and Trae Menard (TNC).


Numerous species of rare native birds are found here, including:

  • 'Elepaio
  • 'Apapane
  • 'Amakihi
  • 'Akikiki (endangered)
  • 'Akeke'e (endangered)
  • 'Ua'u (endangered)
Why TNC Selected This Site

The 7,050-acre preserve safeguards the rich abundance of life that has evolved in upper Wainiha Valley and Alaka'i Summit Plateau. Remarkable examples of healthy native lowland forest, rarely found elsewhere in the islands, can still be found in Wainiha's twin valleys, along with rare Hawaiian freshwater stream communities. The Alaka'i, a mile-high plateau cradled between the mountains, is a wilderness of rare plants and birds. The 12,000-acre plateau sits on the flank of Mt. Wai'ale'ale and at the head of Kauai's five largest aquifers. Not only is the area the island's primary source of water, but its native ecosystems include rare mountain bogs and the islands' most diverse high-elevation rain forest.

What TNC Has Done/Is Doing

This preserve was established by a 10-year conservation agreement between TNC and Alexander & Baldwin, Inc. While the native ecosystems of the preserve are in good condition at present, they face critical threats posed by invasive plant and animal species: fast-spreading weeds such as Australian tree fern, clidemia and kahili ginger, and wild pigs. TNC is working to contain these threats and prevent them from undermining forest health. 



Closed to public due to remote, rugged location.


7,050 acres

Explore our work in this region

Past Webinars

July 2020: Journey into the Heart of Kaua‘i with Melissa Fisher

TNC Kaua‘i Forest Program Director Melissa Fisher guided us on a virtual field trip into Kaua‘i’s remote watershed forests that TNC is working hard to protect.
Recording: Journey into the Heart of Kaua‘i 
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