Cause and Evolution
Cascade: 37 46.173 x 119 40.519; 7800’el. Mariposa Co.
This lightning caused fire has been slowly burning since June 16, in Yosemite’s high elevation Wilderness.
It started during an afternoon thunderstorm on June 15th. The fire has grown to 109 acres. It is burning in a short needle red fir forest between two upper forks of the Cascade Creek.
The fire has slowly smoldered through sparse surface fuels of duff, forest litter and occasionally creating enough heat to ignite brush. The southern perimeter edge is the most active with occasional 6 to 12 inch flame lengths during the hottest part of the day.
Currently, the fire poses no threat to trails, park service buildings, infrastructure or roads, cultural or natural resources.
The fire could potentially grow to 1000 acres over the next month due to typical warm and dry weather for this time of year. Firefighters continue to monitor and scout the fire to determine the potential in growth and spread direction. Although the immediate fire area has a history of lightning, there is no recorded recent large fire history. Normally fuels too wet during this time of year to support active fire growth. Due to light winter snowpack this year, fuels at this elevation are now able to support fire spread and allow this natural fire to play a vital role in Yosemite Wilderness. The nearest historic fire to the Cascade Fire suggest that fires at this elevation, in this forest type, creep and smolder for weeks and only make runs during dry windy conditions.
Red Fir Forest Fire Behavior
Red fir forests burn about every 30 years. Cascade Fire is burning in an area that has not burned in at least 60-90 years. Because there are no resources threatened at this time or in the near term future, allowing this fire to burn in this area, this year promotes healthy, resilient ecosystem function. If resources are threatened, and/or smoke impacts threaten human health, fire managers will reassess the objectives of this fire.
Park Fire Management Objectives
Though California is hot and dry, which is typical for this time of year and there are few fires burning in our region. Other fires nationally are starting to wind down due to cooler weather and monsoonal flow patterns assisting firefighters in suppression efforts. Resources are available to assist with managing the Cascade Fire. The Cascade Fire meets the park fire management objectives of minimal risk to firefighter and public safety, federal and public property, air quality and Wilderness character.
Smoke Visible in the Morning
Light smoke has been visible mainly in the morning hours near Cascade Falls and the community of Foresta. Smoke may become more visible at high locations within the park. Fire managers are working closely with state and local air pollution regulators concerning potential adverse air quality impacts to nearby smoke sensitive areas. Yosemite’s Division of Resources Management and Sciences personnel have installed air quality monitoring equipment within the communities of Lee Vining, Hodgdon Meadow, El Portal and Yosemite Valley. The park’s webcam located at Crane Flat Helibase will capture fire images, which can be viewed at: http://ssgic.cr.usgs.gov/cgi-bin/camHist11.pl?date=120702&camera=1_mobile_ynp_1&lastFrame=true