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U.S. Geological Survey
Open-File Report 03-491
Online Only
Version 1.2

Historical Rock Falls in Yosemite National Park, California

By Gerald F. Wieczorek and James B. Snyder


This report contains an inventory of historical rock falls reported in Yosemite National Park, with data on the location, date, type of slope movement, trigger, size-volume, types of damage, narrative description and reference(s) for 519 rock falls that occurred between 1857 and early 2004. About 330 of these events occurred within Yosemite Valley and most others were in the near proximity, for example, along El Portal Road in the Merced Gorge. This information was collected from review of published and unpublished historical accounts and field studies of recent rock falls. Many more than 500 rock falls undoubtedly occurred during this historical period, but many went unnoticed or unreported because of the small size of individual rock falls or the lack of impact on trails, roads, structures or utilities. This report is an update of a previous rock-fall inventory of Yosemite National Park (Wieczorek et al., 1992).

Open-File Report 03-491 [168-KB PDF file]

Historical Rock Falls Worksheet [888-KB Microsoft Excel Worksheet]

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Contact Information

For questions about the scientific content of this report, contact Gerald F. Wieczorek.

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