Volunteered Geographic Information (VGI), such as contributions to OpenStreetMap and geotagged Wikipedia articles, is often assumed to be produced locally. However, recent work has found that peer-produced VGI is frequently contributed by non-locals. We evaluate this approach across hundreds of content types from Wikipedia, OpenStreetMap, and eBird, and show that these models can describe more than 90% of "VGI flows" for some content types. Our findings advance geographic HCI theory, suggesting some spatial mechanisms underpinning VGI production. We also discuss design implications that can help (a) human and algorithmic consumers of VGI evaluate the perspectives it contains and (b) address geographic coverage variations in these platforms (e.g. via more effective volunteer recruitment strategies).