Our team is part of an effort by the Southern Sierra Critical Zone Observatory, led by Professor Roger Bales (UC Merced), to study snowmelt phenomena in a small, contained watershed in the southern Sierra Nevada. This is conducted through the deployment of large-scale wireless sensor networks.   With 60 wireless nodes and more than 240 independent sensors, this is believed to be the largest eco-wireless system in the world.  Each node in the network is equipped with sensors that measure a plethora of environmental variables, including but not limited to snow depth, humidity, temperature, soil moisture, soil matric potential, and solar radiation. The data is valuable to scientists who wish to understand the Critical Zone, but also provides water management officials with unprecedented real-time conditions, something not possible until now.   Aside from scientific information, these deployments are also shedding much light on the interaction between technology and the environment. Data collected by these networks will improve WSN design and will investigate the feasibility of instrumenting an area as large as the entire Sierra Nevada mountains.