Image 2 - Down the Yuba Aerial View of Marysville from El Dorado: Hydraulic Mining

GIS software is a tool to visualize and explore spatial relationships - to relate information to place. These relationships can vary from hugely complex 3-D models of worldwide ocean currents used as an aid in long term weather forecasting to something as simple as a map providing pop-up information - as suggested in the map linked at the right. This particular map provides visual context for students learning about hydraulic mining and its impact during and after the California gold rush.

The earliest 49ers worked individually and in small groups panning for gold in the rivers and streams of the Sierra Nevada foothills in California. They used small cradles and sluice boxes to separate sediment from the heavier gold flakes and nuggets. By the late 1850s, though, and not ending until the process was outlawed by California courts in 1874, large companies ran hydraulic operations ripping loose millions of tons of soil in the hills and valleys of the Mother Lode region.

This 1871 bird's-eye image of Marysville, California and the Yuba River flowing out of the Sierra Nevada Mountains provides context for exploring the history of the hydraulic operations. Click on the link to engage the map. Students are asked to use this interactive visual to create a travelogue, following not only the geography of the river downstream out of the mountains, but to travel through time, as well, from an 1860 report about the hydraulic mining process, to the court’s 1874 decision banning its use, and, finally, to a contemporary view of the remnants of dredging operations in the gravel washed downstream and flooding farmland around Marysville. The lesson takes groups of students on a trip down the Yuba, sharing information along the way about the brief history of the hydraulic process, discussing the 1874 court decision, and leading to writing a 19th century style travelogue chronicling their trip and their understanding of the hydraulic process and the consequences of its use. The map and the exercise literally provide a contextual framework for linking historical ideas both in time and place.