I just got back from Autozone and that reminded me.
I put in a new air filter (oil and oilfilter) before I left and put another one under the seat. After driving around on dirt roads for two weeks I chucked the first one and put in the second one. Then after following Jimm around on dirt roads and rabbit trails hunting antelope, I got a third one in Gillette and put it in. Finally, just today I chucked the third one and put in a new one. That is four air filters for 9,245 miles.
If you are running a K&N, I would take it out and put in a paper one so you don't have to clean the K&N while you are hunting. Once you get into some altitude the motor will have enough trouble breathing that thin air without having to suck through a clogged air filter. It will also keep your transmission from kicking down everytime you hit a small uphill grade.