This dirt and gravel road forks off of the Mauna Kea Access Road (R-1) and goes uphill passing through open māmane (Sophora chrysophylla), naio (Myoporum sandwicense), and ʻiliahi (Santalum paniculatum) native high-elevation dry forest. Native forest birds such as ʻamakihi (Hemignathus virens) and ʻelepaio (Chasiempis sandwichensis) are often sighted in the vicinity of the road. The route also traverses critical habitat of the endangered palila (Loxioides bailleui), a Hawaiian finch found only on the upper slopes of Mauna Kea. The road leads to the lower reaches of high-elevation alpine desert, with ʻāhinahina (Mauna Kea silverswords, Argyroxiphium sandwicense subsp. sandwicense) occasionally blooming.
Caution: the road takes drivers to over 10,000 foot elevation. Be aware of altitude sickness symptoms.
