According to AllTrails.com, the longest dog-friendly trail in Hawaii is Maunawili Falls from Waimanalo. This trail is estimated to be 14.9 mi long.
Hawaii: With an ascent of 4,307 ft, Maunawili Falls from Waimanalo has the most elevation gain of all of the dog friendly trails in the area. The next highest ascent for dog-friendly trails is Bowman Trail with 3,254 ft of elevation gain.
The most popular and difficult dog-friendly trail in Hawaii is Kuliʻouʻou Ridge Trail with a 4.8-star rating from 7,811 reviews.