Upon entering Mexico, the cyclist specific maps that the states of Washington, Oregon and California provide for the traveller become a thing of the past. Even the comprehensive Adventure Cycling Association maps that cover the whole of the USA stop at the border. If entering Mexico through the Tijuana border into Baja, there is only one real option of the paved highway 1 all the way to the tip of the peninsula.
On the mainland however, there are a myriad of highways, secondary roads and quiet dirt tracks to choose from, if you know where they are…
My research into Mexico maps or cycling routes was limited to tracking the routes of other cyclists whose blogs I had followed during the planning of my trip, most of which consisted of the coastal highway route after arriving on the mainland at Mazatlan. A cyclist who chose a different route is Anna Kortschak, who is currently travelling South from Alaska, and whose blog led me to investigate the Mexican SCT government maps which seem to comprehensively show the highways, secondary and dirt roads.
Instead of the usual process of obtaining the maps from the government SCT offices, only found in state capitals and involving what sounds like a bit of a treasure hunt around various offices, I did some googling and found a treasure trove of the maps in PDF format.
They can be used as a reference on a smartphone or laptop, or a visit to a printing shop should be able to get them blown up to A3/A2 size.