Connie: Flat cookies...

First. I don't know anything about high altitude cooking, but assuming that is not an issue, I might be able to help. I have found that shortening will generally make a soft puffy cookier that doesn't spread as much as a butter one. If you still have a problem when you are using shortening I would think that there is not enough flour in ratio to the shortening. Do you have access to a scale? If so, try weighing the flour instead of measuring by the cup. If no scales are available, you might add a little extra flour to give your dough a little more firmness. You have to do this carefully, because adding too much flour can effect the balance with the other ingredients. I also rotate cookie sheets because putting batter on a hot sheet will cause it to spread. If you want to just use one sheet, try turning it over and running cold water on the under side to cool it. Also, you might want to post this question to Sarah Phillips at the bottom of the list of posting topics. She might have a better answer for you. Oh, another thing, are you using larger than usual eggs? They can make a difference if extra large because that is like adding extra liquid.