"Watershed": various sites.

Three hundred years ago, discriminating travelers in the European countryside might have carried with them an optical instrument called a "Claude glass" after the seventeenth-century French landscape painter Claude Lorrain. A small, tinted mirror, it lent the scenes it reflected a painterly quality evocative of Claude's idealized landscapes. By the early nineteenth century, a set of colored lenses that could be held to the eye was available to American sophisticates searching for scenery on steamboat trips through the Hudson River Highlands. Voyagers used their filters to sweeten the vistas (source of dramatic landscapes by homegrown Claudes like Cole and Durand) with the golden flush of dawn or the silver-blue glimmer of moonlight.

The Claude glass, and the metaphor it provides for how our understanding of nature is culturally constructed, is the inspiration for Matts Leiderstam's View, a key work in "Watershed: The Hudson Valley Art Project," an ambitious program of public art organized by Minetta Brook and installed for the next two years at twelve locations along the Hudson. View consists of a pair of observation deck style binoculars, one on each side of the river, fitted with colored lenses that add "expressive" color to views from a dock near the Bear Mountain Bridge and a belvedere at Boscobel, a grand neo-classical mansion outside Garrison. With its twinned subtexts of sightseeing and voyeurism, Leiderstam's work asks why nature often appeals to us most when framed, and examines how aesthetic gestures within the landscape transform sites into situations.

View interrogates the notion that cultural framing improves the experience of place; meanwhile, the core conceptual ambitions of "Watershed"--to "raise awareness of the imaginative and physical landscapes" of the area through art--rely on it. The exhibition's parameters are loose enough to accommodate a range of engaging site specific public artworks--from Par White's charmingly goofy animal-form barbecue grills at gear Mountain State Park's Hessian Lake to Constance De Jong's Speaking of the River, a pair of audio-enhanced park benches that feature sound tracks documenting the area's history through recorded interviews with local residents, to two conceptually, if not physically, site-specific 16 mm films about the Hudson by Peter Hutton and Matthew Buckingham, respectively, which are shown in adjacent Beacon storefronts.

White's grills will get used, and De Jong's works (literally) speak for themselves, as do the films. But to thoroughly understand projects like Christian Philipp Muller's Hudson Valley Tastemakers on the campus of Bard College, additional explication is required, placing a layer of didactics--yet another sort of lens--between the viewer and the natural world. Evoking both the post-Minimalist sculptural forms of Land art's first generation and the ecologically driven Conceptual strategies of its second, Muller's work is a garden in a rectangular steel box divided into plots containing edible plants sown in the various soils of six different Hudson Valley counties. In keeping with his interest in social systems, the artist has also organized a series of programs related to agriculture and cuisine. Though this information was available on-site, I somehow managed to totally miss it during my visit. Muller's garden was beautiful, healthy and blooming; it provided a salutary window on the agrarian culture of the region. Yet standing there, momentarily absent the project's contextualizing lens, I found myself thinking not about post-Minimalism or land use but about the amazing sunset over the adjacent field. And wondering whether the experience I was having there actually had that much to do with "Watershed."

In fact, this question had begun to percolate earlier that day, when a string of malfunctions conspired to temporarily erase the exhibition from its sites at Bear Mountain just as I arrived. White's grills had been removed for safety-related refabrication; nearby, a twisted wire thwarted the filter effect in one of Leiderstam's binoculars, while an infestation of ants forced De Jong's audio bench offline. These things happen; maintenance issues are inevitable with public art, and I'm told the works were fixed within days. But there in the valley, as I watched rain approach over the hills, the breakdowns started to feel almost serendipitous--emphasizing something about the straightforward pleasures to be found in unmediated perception, making the "imaginative and physical" potential of the Hudson abundantly clear, the e-difying lens of art notwithstanding.