Prescribed Burn- Yosemite Valley Units 11, 13, 15, and 16
The National Park Service is proposing to initiate prescribed burns as early as fall 2020 in the Yosemite Valley outer Wildland-Urban Interface (WUI) area. The proposed burn would cover an area of approximately 222 acres of the park within four of the Yosemite Valley burn units (YV-11, YV-13, YV-15, and YV-16) north and south of the Merced River between El Capitan to the west and Yosemite Village to the east. This project will build on past prescribed fire activities and recent thinning and pile burning work in the area with the goal of reducing fuel loading within the Yosemite Valley outer WUI buffer.
The segments will be burned in two phases with the units north of the Merced River (YV- 13 and YV-15) being burned in one phase and the segments south of the river (YV-11 and YV-16) being burned in a separate phase. The north segments will be held to the north by Northside Drive and to the south by the river. The western holding line will be the Valley Loop trail where it passes through the meadow just west of the El Capitan Picnic Area. The eastern holding line will be the Valley Loop Trail where it meets the road just west of Leidig Meadow. The segments south of the river will be held to the north by Southside Drive and to the south by the Valley Loop Trail. The western holding line will be where the trail meets the road, across the river from the El Capitan Picnic Area. The eastern holding line will follow the section of the Four Mile Trail that runs from the Valley Loop Trail to Southside Drive.
The burn will be conducted by hand ignition using drip torches. Unmanned Aerial Vehicles (UAVs) may be used to assist with igniting the burn if needed. The holding lines for YV-11, YV-13, YV-15, and YV-16 are all currently maintained roads, trails, or natural barriers and no additional ground disturbance is expected. If additional control lines are deemed necessary to facilitate safe burning and to protect resources, they will be reviewed by an interdisciplinary team and approved by the deciding official prior to implementation. The interdisciplinary team is made up of NPS fire staff as well as cultural and natural resources staff (including archaeologists, historians, and cultural anthropologists/tribal liaisons). Avoidance of cultural sites will be necessary and additional survey may be needed. All recommendations for cultural resource preparations listed will be completed prior to ignition.
The Yosemite Valley Unit has a long history of prescribed fire, with the majority of the four segments (YV-11, YV-13, YV-15, and YV-16) having been burned multiple times over the last 50 years. The eastern portion of YV-11 was burned in 1995 and in 2015 most of the segment was burned, with the exclusion of the far western tip. The eastern half of YV-16 was burned in 1993 with the western half burned in 1995. The entirety of YV-16 was last burned in 2015. Segment YV-13 was first burned in 1971 with the western half again burned in 1976. A smaller 10-acre area was burned in the central part of YV-13 in 1990 and again in 2001. The western half was last burned in 2002. The entirety of Segment YV-15 was first burned in 1979 with the last burn occurring in 2008. The 2008 burn covered all but the far northern corner of the segment.