The Laraways visited Yellowstone National Parks sometime before they arrived in Oregon in 1905 (perhaps on their way out). No visit to Yellowstone is complete without viewing the geysers.
I think this is Riverside Geyser because of the way it erupts over the river, but modern views don't show a bridge and indicate the geyser stands alone. But this 1896 view does include a similar bridge and shows a secondary eruption in the background, so perhaps the plumbing of the geyser has changed a little in the past 125 years.
I haven't been to Yellowstone for quite a few years so I don't remember if I saw this geyser.
It sounds like you now have to stand on the other side of the river to observe Riverside Geyser.
It appears that the main road now crosses the Firehole River downstream from Riverside and there are several geysers in that area. Perhaps that is the other geyser we see in this photo.
L.E. on 27th April 2021 @ 8:53am