Splendid was active then, and the best way to catch a series was to immediately notice when one started. Daisy was erupting nice and regular, about every 75 to 80 minutes (excluding wind effects). The initial eruption of Splendid would take place shortly before Daisy was expected, so if you didn't see an eruption at the predicted time, it was time to make a quick bike ride out to see what was going on. So every hour or so, I'd ride my bike over from The Box to the fence that ran along the walkway west of the Lodge. If I didn't see Daisy after about ten minutes or so, I'd head on down basin.
On 06 Aug 1987, around 10:30, I did my usual ride up, and saw a plume of water over on Geyser Hill. It wasn't Lion, and at first I thought I was seeing a North Goggles major. Then I realized that the water column was to the left of Lion, on the wrong side. I had no idea if it was Big Cub, or Lioness, so I got on my bike and went on around the circle to get a better look at Geyser Hill.
As I approached the Visitor Center, I saw Jim Lenertz and Rick Hutchinson looking over there with binoculars. They too had noticed the activity, and wanted to get a better view and to figure out which geyser it was.
It was Big Cub, and fortunately, Phil Landis, who was working as Rick's assistant, was on Geyser Hill near Teakettle, and was able to take this photo. (I don't know how to contact Phil for explicit permission. But it is, as far as I know, one of the few, if not the only, photo of Big Cub in eruption.) We watched the activity for at least 3-1/2 minutes, and I would estimate the height was from 10 to 12 meters. Note also that Little Cub was also in eruption.
Afterwards, Rick went over to checkout the platform there, to see if there were any other changes (or signs of manipulation). I tagged along. Everything looked normal, and if we hadn't actually seen the eruption, we wouldn't have seen any evidence of an eruption. (Other than it was a bit wetter down wind of Big Cub, but that dried quickly). The one interesting thing is that the vent has a little side hole in it. A small jet of water coming from it can be seen in the photo on the left.
And I did see Daisy a few minutes later, so no Splendid activity that day. Or for the next few weeks. But I did see Giant about a month later.
Update: I've been told that Phil took the photo as part of his official duties working for Rick, so it's in the public domain. And that Phil died of cancer a few years back.