By Pierre Ratte
It’s said the only constant is change, and it looks like there may be lots of changes in 2025. And yet, in the tranquility of cultivated and natural landscapes in Sonoma County, morning’s rising sun paints a chamber-of-commerce, picture-perfect day on the road ahead.
Fun Facts: Macadam refers to a road-surfacing material and a method of construction. Developed in 1820, it’s named after inventor John McAdam. His method and material was a major breakthrough improving on Roman stone and cobble construction. McAdam’s invention relied on small angular rocks compacted by traffic to create a self-locking stable and relatively smooth surface.
The success of McAdam’s crushed rock surfacing created dust problems. Low pressure under faster vehicles vacuumed giant clouds of dust from McAdam’s crushed aggregate roads. Thus, in 1902 tar was sprayed on top, creating tarmac. Later, tar was incorporated directly into the gravel mix. This manufactured combination of aggregate and tar is called asphalt, blacktop or simply pavement.
Rock asphalt, or natural asphalt, is distinguished from manufactured asphalt as a naturally occurring petroleum product in solid rock form. Herodotus described Babylonians using natural asphalt in binding roads and fortification walls, Phoenicians used it to caulk shiplaps, and Romans sealed public baths and cisterns with it. The word stems from the Greek asphaltos, meaning “secure.”
Gilsonite is a branded name for rock asphalt. In 1860, Samuel Gilson discovered major deposits of natural asphalt in Utah. He retailed products under the Gilsonite name. The Uinta Basin in Utah holds an estimated 28 billion barrels of Gilsonite, and is one of only two places on Earth with economically significant deposits.
Mines in the Uinta Basin have operated for 125 years. Comparatively, the world’s estimated oil supply is 1.5 trillion barrels; consumption is 100 million barrels of oil per day, 36.5 billion per year. Theoretically that’s 40 years of remaining consumption under static conditions.
