In 1793 and again in 1794 Captain George Vancouver introduced the first beef cattle to Hawai'i Island – 4 males and 8 females. King Kamehameha I placed a kapu or taboo on the hunting of the feral cattle, which remained in place until 1830. By this time the animals had become so numerous and such a nuisance to the native population, that it became necessary to begin hunting them to reduce their numbers.
In 1809 a sailor from Massachusetts named John Palmer Parker arrived in the Hawaiian Islands Mr. Parker married a Hawaiian princess and he soon began capturing and domesticating many of the feral cattle and horses that roamed the slopes of Mauna Kea. This was the humble beginnings of the Parker Ranch which is still in operation today, and has become one of the largest and best known ranches in the country.
The Maunakea Access Road, leading from the Saddle Road (Route 200) to the Visitor Information Station (VIS) at Hale Pohaku passes through lands which are currently used by the Parker Ranch for cattle grazing. A short distance in from the intersection with Saddle Road there's a cattle guard on the Mauna Kea Access Road, and then about 2/3 of the way up to the VIS there's another cattle guard in the road, which marks the upper boundary of Parker Ranch's pastures on this part of Maunakea.
Until 2000 the pastures on both sides of the Maunakea Access Road were open range – cattle could freely pass back and forth across the road. During the daytime, the asphalt heated up from the sun, and at night cattle often congregated on the road to enjoy the sun's retained heat. Many times careless tourists, employees of the observatories, and visitors and staff at Hale Pohaku hit cows with their vehicles. Most of the crashes happened at night when it was foggy and hard to see dark colored cows lying on black asphalt. When asked what had happened after a crash, many startled drivers honestly didn't know what they'd hit. This is how the legend of "invisible cows" on Maunakea began.
Since 2000 Parker Ranch has maintained electric fences on both sides of the Maunakea Access Road, which generally keep their cattle off of the roadway. However, in remembrance of the old days when cattle roamed freely back and forth across the Maunakea Access Road, the Visitor Information Station on Maunakea still sells "Invisible Cow" bumper stickers.
Beware of invisible cows!