The PermaSense project has set the ambitious goal of gathering real-time environmental data for high-moun- tain permafrost in unattended operation over multiple years. This paper discusses the specialized sensing and data recovery architecture tailored to meet the preci- sion, reliability and durability requirements of scientists utilizing the data for model validation. We present a custom sensor interface board including specialized sen- sors and redundancy features for end-to-end data valida- tion. Aspects of high-quality data acquisition, design for reliability by strict separation of operating phases and analysis of energy efficiency are discussed. The system integration using the Dozer protocol scheme achieves a best-in-class average power consumption of 148μA con- siderably exceeding the lifetime requirement.