About Us

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.

SIEN has had recent staff turnover due to retirements and people leaving for other opportunities. The network is in process of hiring a new program manager, and physical scientist, followed later by an ecologist, logistics coordinator, and shared science communication specialist.

Need to get in touch? Here's how to contact us.

Network Staff

Andi Heard, Acting Program Manager

Andi started working with the Sierra Nevada Network in 2004 as a physical scientist. She led lake and river monitoring projects. In 2024, Andi accepted a new position as project lead for the National Park Service Inventory Program. 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.

Sarah Wakamiya

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.

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.