Chappers - It sounds like you have only moderate experience with mapping. Previous replies have mentioned USGS, DeLorme, Benchmark, and Google among others. One thing to remember is that any map - - electronic included - - is at best a snapshot in time of a moving object.
Google, in particular, has real problems in the West showing dirt roads that are on private land and have no access. Google and other mapping websites will even route you down some of them - - which is no fun when you come to a locked gate with a "No Trespassing!" sign on it and a 30 miles detour.
All maps have errors. Things change on the ground. That's why Adventure Cycling has updates and errata for its mapping products. Especially in the West and on dirt roads, there are seasonal closures - snowmelt, critical game habitat, fire danger. Not to mention construction, bridges out, etc.
About bridges, there are thousands of substandard bridges on remote roads which pose a liability risk for managing local governmental bodies. Faced with high replacement costs, many of these are simply being removed. So even if Google satellite shows a bridge - it may no longer be there.
What I am saying - in response to your wish for an "Everything" resource - is that such an animal does not exist. Yes, you can get a combination of sources that are reliable, but you need always to be prepared for differences on the ground - especially in remotes areas such as the West.
