In this territorial map of 1773 Spain had a dominant claim to large areas of North America, as far north as Nootka, Alaska- though some, such as the Northwest and Florida regions, were in dispute and their claim to the Far West needed supporting occupation even though what is Mexico had been occupied by the Spanish for over two hundred years. At this time, Spanish influence extended as far as the Gila and Colorado rivers, and Baja. The land route from the Northern frontier of Mexico was treacherous, and Baja, itself, was too poor to support northern settlement. To ensure continued Spanish possession of Alta the context of the Anza expeditions.