This is from a Roberts & Fellows stereo card. The caption says "The Arkansas R., near Leadville, Col." It doesn't look like anything very close to Leadville, so I'm wondering if it's Brown's Canyon, or in the area of Granite or Twin Lakes. From the close-up at the grade crossing, the track looks narrow gauge, so I don't think it's Colorado Midland. The South Park grade coming down from Climax never gets this close to the river (and the river is smaller there), so I assume it's D&RG somewhere below Leadville. Of course, it is possible that the caption is completely wrong. I found an advertisement for Roberts & Fellows from 1890 so I know they were in business then, but I haven't been able to determine when they started or stopped publishing stereo views, but I'd guess this is 1880s or 1890s. Any ideas on the location?