I researched the same question a few months ago. I was looking to install GPS on a Mini PC so I had a large screen to look at while driving and also install a ballistics program. At that time Garmin looked like it only had their street program available and not the Topo program for a Mini PC. If you go to the DeLorme site and find the forum page, it takes a bit of digging, and search on the correct question you can get the answer. The short version is that BLM has a zip file for each state that has the information as a shape file. That is another hard place to get to so follow the instructions in the forum. It looks like you will have to go to each states BLM web page to get each one. One of the people in the forum has created a batch file that has a fairly nice GUI with it to extract the files and create the shapes in a format that DeLorme can read. You down load the file to the PN-40 and it has the BLM land ownership information coloring just like their maps. It is probably up to date as of the date of the zip file. I plan on calling the Denver BLM office sometime and ask that question. If you do let us know.
As I said I was looking for something for the pickup for GPS when we are driving around and having something like Exball installed so when we found an antelope we could unplug it and throw it in a hard case to take for a short walk to dial in the scope.
I hope this helps.
