I contacted Garmin about their topo maps asked when they would have a 1:24,000 map out.
This was the reply:
Thank you for contacting Garmin.
I don’t have any firm info or inkling on it at this point.
We do not have nationwide 24K Coverage. That is true. MapSource US TOPO 2008 is based on USGS 1:100K data, but with that said it is a hybrid product and is not just like that 100K scale data. But it does have roots in it. If you have not you might use the Map Viewer on the page about it to see the basic detail in the maps…zoom tightly & click “more detail.”
http://www8.garmin.com/cartography/mapSource/topous.jsp
The USGS does have Digital Raster Graphics over most of the States in 24K detail, which are in big part what PC based products commercial products out there have. That's the rub. They are LARGELY raster based. We really need digital, vector detail throughout for product. And the USGS does not have that all over the US, unfortunately. That’s the rub on the scale.
The USGS does have some 24K digital, vector detail...but not all the US in such for that scale. We put the 24K National Parks West, 24K National Parks Central and 24K National Parks East products together using some of the digital, vector detail they had. But there are many holes in this vector detail they offer...you might have a transportation layer for a quad but not a hypsography layer, for instance, in the vector detail. We ran into this a lot just with putting the National Parks products together. To fill such holes, we put quite a few resources into it. But these parks products just cover the specific areas noted/listed on the coverage maps with them.
If and when these are updated/republished down the way, etc. I assume new coverages will be added. But it could be a pecking order on that.
And the engineers may take some novel approach before it is over, too. Frankly I do not know just what the future may hold in all this right now. This gets requested a lot, though, and we do listen to the market and our customers about what they want. Add to that Magellan has announced something with NG TOPO! I think it is just raster images with a vector layer or two, but it is something. Garmin has never been one to sit back and let a competitor take a run on them.
So stay in touch and check with us periodically.