Thanks for the link for free maps. I am sure that others will find that helpful. Unfortunately, I found very few that would be compatible with my unit and none in my area.
I just wanted to provide a follow-up in case anyone reads this thread. The good folks at REI gave some really good advice, which I will post below:
The 100k and 24k designations are references to the detail provided in the map. The 100k maps are similar in detail to the 100k maps produced by the USGS, where 1 inch on the map is equal to 100,000 inches (1.58 miles) in the real world. The 24k maps are similar in detail to the 24k USGS topo maps typically known as "Quads," where 1 inch on the maps is equal to 2,000 feet in the real world. As you might imagine, the 24k maps have about 4 times as much detail as the 100k maps.
Another advantage of the 24k TOPO series from Garmin is that the roads are "routable," which means that your GPS will be able to direct you to your destination with turns on appropriate roads. The 100k TOPO series is not routable, it is simply an image file with the topographic lines. With the 100k TOPO series, your GPS wouldn't recognize the roads and would simply try to direct you to your destination in a straight line.
In general, for the activities you describe, I would definitely choose the 24k maps.
As you noted, Garmin maps are available on DVD and microSD card. The advantage of the DVD maps is that you can plan your route with Garmin's software, and then download that route information to your GPS unit. The advantage of the microSD card maps is that you don't have to deal with downloading the maps from your computer, you simply plug the card into your GPS unit. You can still upload and download route and track data to and from your computer, but you can't view the Garmin topo maps from your computer.
