Vassar College has always been home to an exceptionally fine collection of Hudson River School paintings. The intimate exhibition currently at the Frances Lehman Loeb Art Center combines nearly 20 of these works with paintings and drawings loaned from two other collections. Together, the 50 small to medium-size pieces show off the strengths of a uniquely American movement, and its wonderfully unself-conscious pursuit of the dramas of nature — its spaces, textures, and especially its suffusing light. By assigning each collection its own gallery, the installation also invites a comparison of the individual collectors’ differing motives.

The first room features paintings owned by contemporary collectors Alvin and Maryann Friedman, who were originally inspired to purchase Hudson River School paintings by an exhibition of such works at Vassar in 1983. (Mrs. Friedman is a Vassar alumna; Mr. Friedman graduated from Cornell, where these paintings were on display earlier this year.) A surprisingly large number of their paintings depict foreign scenes, the upshot of “grand tours” of Europe and the artists’ pursuits of exotic locations. The late afternoon light in Sanford Robinson Gifford’s “Derwentwater” (1855) lends a gemlike clarity to a panorama of English fields, lakes, and mountains. In Frederic Church’s “Andean Sketch” (c. 1857–59), small figures regard Ecuador’s snowy peaks from a lush foreground jungle, while an immense iceberg dwarfs a seaside settlement in William Bradford’s “Labrador Fishing Village” (c. 1885). In such paintings, tiny human figures appear alone but never lonely before nature’s plenitude; the artists seem to have an unbounded faith in the virtues and virility of the natural world. Only rarely does this enthusiasm descend to habit, as it does in Jasper Francis Cropsey’s “Fall Landscape” (1891), in which rosy foliage and a beam of sunlight feel like routine seductions.

The middle gallery displays works from the museum’s own holdings, most of them originally purchased from the artists by the Reverend Elias Lyman Magoon (1810–1886). Matthew Vassar bought the reverend’s sizable collection in 1864 for his new school, making Vassar the first American college to be founded with an intact gallery collection. The selection hanging in “Trilogy” neatly complements the Freidmans’ paintings, while emphasizing local Hudson River and New England scenes. Church brings his gifts to a native subject, a forest in resplendent color, with his “Autumn in North America” (c. 1856). Residents of the Big Apple may especially appreciate Charles Herbert Moore’s “Morning Over New York” (1861), which depicts the city from a vantage point in New Jersey, turning it into a busy horizontal gleam interrupted only by dozens of tiny spires.

Improbable as it may seem, the Dia Art Foundation, known for its Minimalist works and other ’60s and ’70s art, loaned the Hudson River School drawings filling the third gallery. These were purchased by the artist Dan Flavin (1933–1996) some 30 years ago for a museum he had planned to establish near his residence in Garrison, a half hour’s drive down the river from Dia’s Beacon location. The proposed museum merged with Dia, which in 2001 presented the drawings to Vassar as a longterm loan.

The Friedmans and Reverend Magoon likely shared certain motivations as collectors — an appreciation of the paintings’ sheer beauty, and perhaps also a desire to support homegrown art — but the drawings no doubt held additional meanings for Flavin. Drawings are by their very nature more abstract than paintings, and the sketches of the Hudson River School painters are particularly so, relying as they do on fine outlines and occasional patches of tones to separate mere portions of paper into vast spaces.

Their skeletal modeling gives them a modern aspect. Moreover, they show how the complex observations of the paintings derived from the most elemental of forms. In John Frederick Kensett’s “From Rose Island, Killarney” (1856), large clumps of mountains, their great masses captured by simple graphite outlines, settle atop a horizontal filament: the distant shore of a lake, its broad, receding surface located by the barest hints of reflections. The rich tones of a graphite drawing from 1858 by Aaron Draper Shattuck lend a more atmospheric touch to a vine-covered boulder, but here, too, facets of space are separated with a surgeon’s precision.

Flavin would undoubtedly have appreciated the subject of Robert Havell’s undated sheet of studies of West Point, viewed from across the river in Garrison. But Flavin’s own investigations with fluorescent light fixtures suggest a different, deeper empathy with each of these drawings. After all, in a very different medium, he also pursued the tensions between planes and contours, between permeating illumination and its keen divisions.

Until October 21 (Vassar College, Poughkeepsie, N.Y., 845-437-5632).