The first Europeans in what is now California were probably soldiers and Catholic missionaries from Spain. They founded 21 missions from San Diego to Sonoma. The missions are currently connected by what is known as El Camino Real — The Royal Road. It is about 600 miles long.
The missions are approximately 30 miles apart, what would have been a day’s journey on horseback. Tradition says that as the padres journeyed from mission to mission, they scattered wild mustard seeds along the sides of the road, especially where it winds, to mark a bright yellow trail in the hills.
I live four miles from Interstate Highway 101 which follows the route of the historic El Camino Real. Where I live is between the missions in San Luis Obispo and San Miguel. Whether the padres dropped the first mustard seeds here, I don’t know for sure, but I can testify that wild mustard grows along the wild places in the hills, in empty lots, and along the roads. Their seeds got here somehow.