Doing Research. Finding AWESOME Information

I have been feeling intuitively that the famous Seattle Underground tour covers only a very small part of what's left of the old labyrinth system of underground city sidewalks from previous centuries. I'm writing about such in my novel but it's very difficult to find verifiable information (beyond what I can see in my head and feel in my gut).

Meanwhile, I found a most entertaining post on this topic, written by a very talented writer. I hope you take time to read it (if you're interested in homeless, and the idea they've made a home out of the rain by living underground, as I "get" they really do).

Here's that fascinating account: http://explorations.undercity.org/2008/04/seattle-searching-for-underground.html