I'm always in the middle of half a dozen books. One of the ones I'm reading at the moment is The World Rushed In, which I picked up at a garage sale for a buck.
(Garage sales and library sales have ruined me for regular book-buying. If it costs more than a dollar, I can rarely bring myself to buy it.)
When I picked it up, I thought it was a basic historical account of the Gold Rush. It turns out to be a much more interesting thing: one man's Gold Rush diary, supplemented with excerpts from other Gold Rush diaries.
The book is 460 pages plus appendices, so I'm (opening spreadsheet, running calculation) 60% of the way through.
They're just arriving in California, way at the top of the state, still weeks away from the Sierras and the gold mining regions.
It's been fascinating to see how steadily he's kept his diary, how he's written home every chance he got (once past Independence, MO, that's been all of twice, I think), how much he thinks about his wife and baby daughter, and his brother and mother, all left behind on the family farm. He's hoping he can bring back enough wealth for them to have an easier life - maybe one with enough money and leisure so they can travel the plains and the West together, simply to enjoy the beauty of the place.