You can download an area map and then use it offline. Take a look at the steps below.
"1.Open the Google Maps app maps.
2.Make sure you're connected to the Internet and signed in to Google Maps.
3.Search for a place, like San Francisco.
4.At the bottom, touch the bar that has the name of the place you searched. If you search for a place like a restaurant, touch More three vertical dots.
5.Select Download .
Tip: The biggest size for an offline area is 120,000 square kilometers. If you try to save an area bigger than that, you'll be asked to zoom in to a smaller area.