Originally Posted by wsbsteven

Use Google Maps offline cache feature. You'll find it in the lab (settings, labs, pre cache). To use it type in your city or location and search, then press the pin point on the map and select pre-cache map area. The maps do expire but you can do this at a place where you will have data access before going on your trip. I don't believe navigation works with it though but I haven't tried it.

Official Google Blog: “Download map area” added to Labs in Google Maps for Android