Your directions worked fantastically. I was able to transfer the file to my eTrex with absolutely no issues, save the basemap one that I mentioned above. Clear and concise - and convenient too. Thank you for making this available.
For what it's worth, I was able to find the other zip file that you had available on your ftp directory - the one that had the individual .img files of the large CA file. This one actually worked out a little better for me. I was able to download it and import the individual files into Mapsource using cgpsmapper. That way I can load up all or selected portions of California as well as some other areas that I refer to. I was also able to add more detailed roads from Metroguide - on the eTrex, they're overlaid onto the top of your contours. This way, it's the best of both worlds - your fantastic contours and trails and the more recent streets and POIs.
For what you're using it for, I agree on the tradeoff between current streets and more accurate trails / contours / etc. Most of the information I've found echoes what you've seen in the USGS SDS datasets. I'm not sure what you used for processing the data prior to import, but if you used Global Mapper, you should be able to select the layers you want to keep. That way you could just provide the trails, wells, hydrography, etc and filter out the roads. Let me dig up what I've got in the form of other datasets. I may have come across some other relevant areas for you. BLM boundaries might be handy for you and vegetation sets too.
Tiger data from the US Census bureau might be the way to go for that. Open Street Maps has a large repository of data from Tiger and other sources that's able to be imported. I've only touched on this in the last few weeks though, so I'm new from the GPS aspects. The GIS data I'm a little more familiar with.
You might also be interested in FAA obstruction data (towers, etc), particularly if you're calling in any kind of air support. Airspaces such as Class D, C and B might be handy and frequencies of local CDF or SAR branches might be useful. All that can be georeferenced to the towers or sites.
I think it was a good compromise and I agree at the utility for 20 ft intervals. I hike and kayak around Sacramento and Nevada County and find having what you describe as being close to ideal.
See above. Importing it all through cgpsmapper and mapsettoolkit works wonderfully. As far as viewing it from a greater distance, I'd say it's somewhat of a nit. I think it's correctable, but terrain from that distance is hard to distinguish anyway. Is it worth it? Maybe not at this time. It's not quite the product be used for terrain avoidance while flying or driving anyway. Its something that just looks purtier.
Again, thanks for making it all available. Though I called it out as a little glitchy on my GPS, I love it and have been marvelling over it since I downloaded it.
-Brian