The Wisconsin cartographer who mapped Tolkien's fantasy world

I love fantasy in general, and have read a ton of it. other than tolkien, I have never read a novel with that strong a sense of geography in a constructed world - specifically, that there is an entire rich land out there, and not just a graph of interesting places with the focus shifting from one point to another. when the hobbits have to go from the shire to rivendell, or aragorn has to take the paths of the dead to reach his destination in time, tolkien really manages to convey the experience of a difficult journey that takes a significant amount of time even when nothing plot-significant is happening along the way.

Pratchett's Discworld is pretty well mapped out and that which is left to the imagination is well described. Death's house and garden seem almost tangible ...

pratchett is my all time favourite writer, and I love the discworld series, but I never got a good sense of the "spaces between" the way tolkien could do it - e.g. the logistics of traveling from ankh morpork to the ramtops were alluded to, but the journey scenes never really came alive for me in the way that scenes set within ankh morpork did.

the deverry series did come close, and to some extent the wheel of time books (though it's been a while since I read those).