The Sierra Nevada Network (SIEN) is one of 32 National Park Service inventory and monitoring networks across the country that monitor the condition of park ecosystems. SIEN works with four parks: Sequoia and Kings Canyon, Yosemite, and Devils Postpile. Interested in seasonal field positions? Visit our Work with Us page.
SIEN is responsible to a board of directors and technical committee composed of park superintendents and staff. Program guidance and oversight is also provided by the National Park Service's Inventory and Monitoring Division. The network leverages staff and resources by collaborating with parks, other networks, and partners.
Need to get in touch? Here's how to contact us.
Rachel Wolstenholme, Acting Program Manager
Rachel Wolstenholme has worked as a Biologist for the NPS and non-profit organizations for over 25 years. Her focus has been on endangered species recovery and includes work in Yellowstone, Glacier, Pinnacles and Channel Islands National Parks. Since 2020 she has been serving as our regional wildlife biologist. Rachel's first role with NPS was leading a dynamic team at Pinnacles National Park focused on California Condor recovery. Her projects have ranged from gray wolf monitoring to island fox recovery, as well as wolverine and spotted owl surveys. She conducted water quality and quantity monitoring for several years in Wyoming's Wind River Range. Rachel’s M.S. degree from the University of Montana focused on human-wolf interactions in a rural ranching community. Along with her focus on finding common ground and endangered species recovery, she believes in strong collaboration with universities and partnering with NGOs. In her free time you’ll find Rachel enjoying the trails of our parks.
Sarah Wakamiya, Data Manager
Sarah joined the Sierra Nevada Network in August 2021. In her role, she designs and manages applications and workflows for storing, analyzing, and sharing network data. She has been a Data Manager with the I&M program for over a decade, previously working at the Mid-Atlantic Network, Northern Great Plains Network, and most recently the San Francisco Bay Area Network. She has a B.S. in Neurobiology and Physiology from the University of Maryland – College Park and a M.S. in Wildlife Ecology from Southern Illinois University – Carbondale. Her research as a graduate student focused on landscape-linked population dynamics for peregrine falcons and swamp rabbits. These days she is particularly drawn to the interaction of data and art through data visualization and loves learning about the different biological systems the I&M program monitors. When she’s not solving data puzzles, she enjoys trail running, rock climbing, art (drawing, watercolor, and photography), and trying not to injure herself while learning to ski.
Erika Blomdahl, Ecologist
Erika Blomdahl started as the new Sierra Nevada Network Ecologist in early July 2022. The ecologist manages our high elevation forest and wetlands monitoring projects.
Erika is pursuing her PhD in Ecology from Utah State University. Her dissertation explores disturbance regimes, their climatic drivers, and disturbance interactions across montane and subalpine forests of western North America. She is also a Fellow in the Climate Adaptation Science program at USU and is involved in research on the social dimension of fire in California.
Previously, Erika coordinated the development of the Utah Fire Atlas, a state-funded project to improve monitoring of trends in wildland fire across the state. She has also managed a forest dynamics lab, and has spent many seasons in the field and camping throughout the West. Her master’s work, at Utah State University, explored fire refugia and endangered species habitat in the southern Sierra. She has a B.S. in Conservation & Resource Studies with a Forestry minor from U.C. Berkeley. When she is not learning about forests, Erika thoroughly enjoys trail running, backcountry skiing, yoga, reading, and gardening.
Andi Heard, Physical Scientist
Andi has worked with the Sierra Nevada Network since 2004 and is the lead for lake monitoring, river monitoring, and climate reporting projects. She previously worked for NPS and USGS in Sequoia and Kings Canyon National Parks, where she supported watershed and air quality research and monitoring, a study on the effects of contaminants on amphibians, and research related to fire and non-native plants. Andi has a B.S. in Chemistry from the University of California, San Diego, a M.S. in Watershed Science from Colorado State University, and a Ph.D. in Soil and Water Science from the University of California, Riverside. Her areas of interest include water quality and biogeochemistry.
Linda Mutch, Science Communication Specialist
Linda worked as the Sierra Nevada Network Program Manager from 2002 through 2009, and left this position in January 2010 to pursue her interest in science communication through a new role with the network. Linda works with network and park staff and cooperators to communicate inventory and monitoring results.Before joining the network, Linda worked as a 5th grade teacher, an ecologist with the USGS Sequoia and Kings Canyon Field station studying forest population dynamics, a biological technician with the National Institutes of Health in Montana, and a park or biological seasonal technician in numerous western national parks. Her interests include fire ecology and forest dynamics, as well as science education and communication. She has a B.A. in Biology from the University of Oregon, a M.S. in Watershed Management from the University of Arizona, and an elementary school teaching credential from California State University, Fresno.
Seasonal Staff - And the Paths They Travel from Here
In the late spring, summer, and early fall our office building becomes more lively and busy than usual, when our seasonal staff arrive to conduct some of the most critical work of long-term monitoring - the field data collection! Without them and the data they collect, we would not have a long-term monitoring program. The seasonal staff who are drawn to our program love to spend their time in the extensive wilderness of our large parks, they become experts at packing backpacks efficiently, cooking with campstoves, navigating to remote sampling sites, and collecting excellent quality data. Some love it so much they come back for multiple seasons, and our program benefits from the long-term knowledge they bring to monitoring projects. They also appreciate the beauty of where they work, and getting to explore large chunks of the stunning wilderness of these parks.In the following series of articles, some of our former seasonal staff share their forays into graduate school, and in some cases how their work here helped motivate and inspire them to continue their education, and explore in more depth the environmental sciences they were able to participate in here, and have the opportunity to do projects of their own.
Last updated: May 3, 2024