While the Alpha comes with the preloaded TOPO map you also have the option of adding additional maps both in the Onboard Memory Capacity and via the Micro SD Card Slot.
Extra map space allow you the option to use multiple maps in the same handheld.
Garmin has also included the option for loading highly detailed Birds Eye Satellite Imageryinto the Astro 320. By now, most everyone has seen Google Earth, and the Bird's Eye maps are very similar. For $29.99 a year, you can download these aerial images into your Garmin Alpha
Quickly transfer high-resolution satellite imagery to your Garmin handheld device to get a true representation of your surroundings with a 1 year subscription to BirdsEye Satellite Imagery. Use your BirdsEye Satellite Imagery subscription with BaseCamp software to quickly transfer an unlimited amount of satellite images to your Garmin device and seamlessly integrate those images into your handheld's maps whenever you need them. Transfer an unlimited number of satellite and aerial image segments to your device with this subscription and free software BaseCamp. High-resolution sub-meter color satellite imagery captures the world in brilliant clarity and detail. Allows you to layer the Garmin vector maps on your handheld (such as TOPO 100K, TOPO 24K or City Navigator) with BirdsEye Satellite Imagery for a real-life view of roads, buildings and terrain. Makes it easy for hunters to perform preseason scouting, determine placement of stands and locate game pinchpoints. Helps hikers and campers find trails/trailheads and clearings for camping areas. Lets geocachers determine the terrain type around a cache and identify parking areas close to the caches. Allows travelers to view tourist hot spots and landmarks from an aerial view to make excursions memorable without getting lost.