I recently got an e-mail from Nancy asking, “Why are my cookies always flat?” It turns out that she lives in Calgary and the increased altitude is affecting her baking. Fortunately there is lots of help these days. A recent book by renowned baker, Susan G. Purdy, is devoted to high-altitude baking. You can learn more at highaltitudebaking.com. There is also a wealth of information at kingarthurflour.com and swcoloradohome.com.