By 1767, the Spanish were determined to colonise California.
They felt pressure from the North.
The Russians had settled in today's Alaska and had developed a lucrative fur trade in which the English also wanted to get involved.
Fun fact : you can still visit the Russian colony of Fort Ross, north of San Francisco, which was settled by the Russian fur traders in the 19th century.
The Spanish finally saw the potential of California and decided to head north.
The Portola Expedition of 1769 was the first Spanish land expedition.
It left Baja California with 3 galleons and 2 mule trains.
The land expedition reached the meeting point at San Diego after walking 300 miles.
The maritime support reached the meeting point in 4 months, losing one ship and 74 of the 90 crew to gangrene.
They continued north and kept walking until they reached San Francisco Bay.
When they returned to Baja California, there was consternation that they had not found Monterey.
A leading friar commented : "you come from Rome without having seen the Pope!"
The whole trip had taken 6 months and covered 1200 miles.