As humans venture back to the Moon, or onward to near-Earth objects and Mars, it is expected that the rigors of this exploration will far exceed those of Apollo . Terrestrial analogs can play a key role in our preparations for these complex voyages, since in addition to their scientific value, analogs afford the exploration community a means to safely prepare and test exploration strategies for future robotic and human planetary missions. Many relevant analog studies exist, and each is focused on a particular aspect of strategic development. Some analog programs such as the Pavilion Lake Research Project (PLRP) present the opportunity to investigate both real scientific and real exploration scenarios in tandem. The activities of this research program demand the use of techniques, tools, and strategies for underwater scientific exploration, and the challenges associated with the scientific exploration of Pavilion Lake are analogous to those human explorers will encounter on other planetary and small solar system bodies. The goal of this paper is to provide a historical synopsis of the PLRP's objectives, milestones, and contributions to both the scientific and exploration community. Here, we focus on detailing the development and deployment of an integrated science and exploration program with analog application to our understanding of early Earth systems and the preparation for future human space exploration. Over a decade of exploration and discovery is chronicled herein.

ABSTRACT This fi eld trip guide explores the interactions among the geologic evolution, hydrology, and fluvial geomorphology of the central Oregon Cascade Range. Key topics include the geologic control of hydrologic regimes on both the wet and dry sides of the Cascade Range crest, groundwater dynamics and interaction between surface and groundwater in young volcanic arcs, and interactions between rivers and lava flows. As we trace the Willamette and McKenzie Rivers back to source springs high in the young volcanic rocks of the Cascade Range, there is abundant evidence for the large permeability of young lava flows, as manifested in streams that dewater into lava flows, lava-dammed lakes in closed basins, and rivers that emerge from single springs. These dynamics contrast sharply with the older, lower permeability Western Cascades terrane and associated runoff-dominated fluvial systems. On the east side of the Cascades we encounter similar hydrologic characteristics resulting in complex interactions between surface water and groundwater as we follow the Deschutes River downstream to its confluence with the Crooked River. Here, deep canyons have cut through most of the permeable part of the geologic section, have been invaded by multiple large intracanyon lava flows, and are the locus of substantial regional groundwater discharge. The groundwater and surface-water interaction in the Deschutes Basin is further complicated by surface-water diversions and an extensive network of leaking irrigation canals. Our west-to-east transect offers an unparalleled opportunity to examine the co-evolution of the geology and hydrology of an active volcanic arc.