Another option is using national forest maps - most are available in plastic.
They would be bulkier and the number of maps you would need would probably equal the cost of the GDMBR.
Since you are from Chicago, I don't know how much experience you have using USFS maps.
The biggest advantage they offer is detailed information of the entire area - not just a specified route.
And they allow you route options as well as the ability to drop into nearby towns.
They are available online or in twons along the way with forest service offices.
(You can always mail them home as you use them.)