Chased Down a Creak

Some time last year my bike started creaking whenever I would climb out of the saddle. A few weeks before moving to Colorado I finally decided to do something about it. I figured it was the bottom bracket, since it had over 5,000 miles on it, so I installed a new one. That wasn't it. Still creaking. Oh well, it didn't bother me that much. Until I started riding in Colorado, and every ride I do has multiple climbs out of the saddle. So last week I decided to make an effort figuring out what was causing it. I cleaned and greased the chainring bolts. That wasn't it. I cleaned and greased the pedal threads. That wasn't it. I cleaned and greased the seatpost. That wasn't it. I cleaned and greased the headset cups. That wasn't it. I cleaned and greased the stem faceplate bolts. That was it. Silence.