Environmental scientists frequently engage in ”campaign-style” deployments, where they visit a location for a relatively short period of time (several weeks to months) and intensively collect measurements with a combination of manual and automatic methods. We present K2, a mote-based system which brings high-quality automated monitoring to deployments of this nature. We identify key application requirements, describe the design and evolution of K2, and present performance results from two field deployments (the largest lasting ~ 5 weeks and including 50 sensing nodes). Our results indicate that K2 is a viable scientific tool, achieving data yield > 99% and producing accurately time-stamped data, even in the absence of a persistently available reliable clock source. These results point a path towards WSN deployments managed by non-CS specialists.