I can never remember if software mapping posts go here or elsewhere, so I couldn't link to previous discussions. But anyway...
I have mentioned that I find www.caltopo.com
to be a superior website for creating custom maps. They have a variety of layers, from Google to historical USGS to USFS to aerial photos, Canada, and on and on. You can print high-def PDFs, or send links, get waypoints, etc. It interfaces with Google Earth and some Garmins.
But I discovered a use that's really handy for us. Click the "about" link and scroll to the bottom and get to the caltopo.com/offline site. With it you can create a custom map that caches in your browser (works with Chrome and Safari; haven't tested all). Since it's cached, it's available offline. Worked fine on my iPad. You can add the layers you like and other info. Handy if you need a specific layer but perhaps your Garmin or app doesn't do that particular map.
And BTW, he's finished the peak view feature. Zoom in to a peak, and control-click to get "view from here." You get a wireframe like the app Peakfinder (or peakfinder.org on the web). But unlike the latter you can switch to a satellite view, and see what it really looks like. Very awesome.
And if you like that, try the viewshed layer. It portrays in 2d what the view covers from a particular location. Great if you want the campsite with the widest view, or wanna make sure you can see the lake from there, etc.
And a somewhat related site is gmap4, http://www.mappingsupport.com/p/gmap4.html
. Very useful for creating custom maps and links to them. It also uses caltopo as a source, and also mytopos.com. It's also free for non-commercial use. Check out a sample here (particularly if you're visiting Big Sur):http://www.mappingsupport.com/p/gmap...5651&z=10&t=t4
The cool thing is how you can zoom in through different source layers all in one map.