Hello everyone, it has certainly been a long time since
I was active here. That's what moving to Oregon gets you.
In one of my Facebook groups, someone shared this photo from the Water And Power Association website, looking north from approximately
300 N. Main. (Colorization as on W&P site.)
Here's a tighter view. For orientation purposes, I have marked the Plaza Church belfry, the Merced Theater, and the partially visible roof of the Masonic Hall, all building that are still standing today.
In the distance, notice the surprisingly large building whose roofline and nearest corner I have outlined in orange, and what may have been an exterior stairway leading to an entrance, outlined in red.* It appears to be at least two stories,
given that it's visible beyond the church, and only the top of part of that is visible.
Here's a still tighter crop:
What on earth was it? I'm frankly flabbergasted that there was such a large building there of any kind when this photo was taken.
The exact location is hard to judge as the depth of field seems to be highly compressed, but I'm thinking this could have been across the street (north of) where Italian Hall is now, given the orientation of the building, but there hasn't been anything nearly as large since 1880, that I can think of.
On the FB post, we've been kicking the football around on this for awhile but we haven't come up with a definitive answer.
*What looks like a stairway could possibly be the end of a gable roof
on a nearer building, although the perspective doesn't look quite
right for that.