Back in the days before the reservoirs were built on the Gunnison River, it could flood a mile wide at Delta in the Spring and be nearly dry by fall, leaving just a sandy desert river bottom with little water. That could explain the absence of water in the photo that might have been taken down in the canyon near Dominguez.
The area around the rock outcropping was planted with orchards many years ago. Often, the river would be re-channeled when the land was reclaimed for farming--another possible explanation for the deviation from what Google maps shows today.
There is an area in the canyon near Dominguez where the original narrow-gauge line actually crossed the river to the west side for distance then crossed back to the east side. In that area, there was a hunting lodge built, the ruins of which can still be seen on the west side of the river. Teddy Roosevelt was purported to have stayed there at one point. When the line was standard-gauged, the track was re-aligned to stay on the east of the river for the entire distance from the bridge west of Roubideaux all the way to Grand Junction.