Peter and Toni Thompson removed the 180-year-old heritage oak tree to move it to another home they built adjacent to the property. More than 3,000 cubic yards of dirt was also removed in the process.
The tree, two others they removed and a dozen others along a previously undisturbed path they bulldozed died, along with surrounding vegetation.
The Sonoma County Superior Judge sided with the Sonoma Land Trust, saying the Thompsons knowingly violated the conservation deal and said they demonstrated "arrogance" and "disregard" over the terms of the easement. The fine of $586,000 will go toward environmental restoration on the property.
The couple, who decided to sell their estate for $8.45 million after the ruling, are seeking a new trial, reasoning their attorney could not properly represent them for personal reasons.