My wife and I had just finished a short walk near the gate and were ready to leave when the shuttle returned for its last trip out to the bridge so we decided to 'go along for the ride'. Sometimes you just get lucky! I got off at the bridge (the stopover lasts about ten minutes) and started chatting with someone who told me that there was a tree full of monarchs about halfway back to the main gate. His directions were a bit confusing but even though they were far from the road and pretty high up in the tree I did manage to spot them. We stopped and I took some stills and a couple of videos with my wife's Canon SX210; my best guess is that there were several hundred butterflies but it was early and I suspect that by sunset the numbers would have increased substantially. Weather permitting I would be there at sunrise tomorrow morning but we're booked for a seniors zoo trip so that's out (boo hoo). Btw, while we were admiring the monarchs a man on a bicycle stopped and told us that he had seen thousands the day before near the lighthouse.
For anyone who reads this and IS interested in trying to see them before they leave, they will be facing the rising sun in the am but you've got to get there early because if flying conditions are favorable they usually leave very soon after sunrise.
We also got excellent views of a GBH sitting on a pole in one of the inner ponds.