The GM's Toolkit booklet (that comes with the thick and sturdy cardstock screen) is what you're after. It's thirty-two pages of random encounters for city and wildeness environments and includes a section entitled 'The Great Wilds' that includes tables and text for 'Roads, Forests and Farms', 'Natural Hazards', 'Wilderness Encounters', 'Outlaws and Animals', 'Villages Towns and Settlements' and 'Something Strange'. Each table has 20 entries of around fifty words, many of them quite evocative. The passing of BI has limited it's availability somewhat, but if you can locate a copy at a decent price it's well worth a look.