Hawaii State Highway 200, also known as "Ala Mauna Saddle Road'' or simply "Saddle Road,'' cuts across the heart of the Big Island. It starts in downtown Hilo and terminates south of Waimea at State Highway 190, twisting and turning through some precarious mountain terrain as it passes by the Mauna Kea and Mauna Loa volcanoes. Along the way, the road reaches a maximum elevation of 6,632 feet.
Saddle Road was originally opened as a gravel road during World War II. It provided access to an Army training area located within the Big Island's interior. It was also intended to serve as an inland evacuation route, should Japanese forces have attacked the Big Island. It remained a secondary route until 1949, when the road was paved for the first time.
Until 2007, Saddle Road was so poorly maintained, narrow and hazardous that some rental car companies would not allow their vehicles to be taken there. Even the best-kept parts of the old road were posted with speed limits of only 35-45 miles per hour.
However, many improvements have been made in the past few years, including the resurfacing of a seven-mile stretch that now allows speeds up to 50 miles per hour. According to the most recent reports from local sources, the route is not nearly the danger (or the fun) that it once was and is becoming a viable alternative to State Highway 19 as a shortcut between Hilo and Kailua-Kona.
Specific areas of improvement have been the new alignment between mile markers #28 and #35, which opened in 2007 and the reconstruction of the existing road between mile markers #19 and #28 in 2008. The latest phase is a rerouting of traffic between mile markers #35 and #42 near the Army base. Additional improvements are planned between mile markers #6 and #19, too. And a southern bypass around downtown Hilo has made it easier to access Saddle Road's eastern end.
Much of this construction has been paid for by the U.S. Department of Defense, who deemed the realignments necessary to move the route away from the Army base. As the first phase was completed, the phrase "Ala Mauna'' was added to the road's name, meaning "trail to the mountains.''
There are a number of interesting sites to see along the drive, not the least of which are the lava fields of the Mauna Kea and Mauna Loa volcanoes, which cover the "saddle'' between the two. One side road takes visitors to the Onizuka Astronomy Complex and Visitors Information Station on Mauna Kea. Another leads to the weather observatory on the north slope of Mauna Loa.
Drivers are advised that sections of Ala Mauna Saddle Road are still quite narrow. Pavement edges can be rough and head-on collisions are still a real problem. Dense fog mixed with volcanic ash, called "vog,'' can make visibility poor. Reflectors have not been installed west of mile marker #35, so night driving can be tricky. At one time, the road's accident rate was 80% higher than that of Hawaii's two-lane rural highways on average, but thanks to the improvements, that statistic is now dropping steadily.