Try Caltopo.com. You can view multiple map sources, and add various layers, such as public land boundaries, shaded relief, and active fires. Best of all, it's free!
You can also export these maps to PDF for printing.
And another feature is to transfer these maps to your Garmin. You are however limited by Garmins custom map size (around 100 tiles on most models). But, as others mentioned, in the field I prefer to use my smartphone with cached TOPO & Aerial maps.