University of Michigan emeritus art professor Wendel Heers’ River Gallery-sponsored “Site and Surround” presentation is as rare as any artwork we’re going to see locally this year — or for many years to come.

A large part of this is because the exhibit is at Heers’ residence, and open only during guided tours. But more so, it’s the scale of the art that Heers is exhibiting that makes “Site and Surround” a once-in-a-lifetime opportunity; this sculpture couldn’t be relocated without monumental effort. Many of these sculptures are simply too big to be shown elsewhere.

Interestingly, Heers’ smaller-scaled works currently on display in an accompanying exhibit at Chelsea’s River Gallery amplify his working manner without the overwhelming dimensions. These works — like Heers’ work previously shown by the River Gallery in 2003 (“Stone/Metal/Found Forms”) and 2006 (“Stone, Metal and Found Objects/Installations and Sculptures”) — are marked by the figurative abstraction he crafts out of hand-shaped wood, stone, and metal.

Reprising “Three Conquistadors” from his 2006 exhibit, Heers’ wall-mounted trio is a sophisticated melding of natural and man-made materials that’s been carved and fitted until each artwork falls somewhere between portraiture and abstract sculpture. Likewise, “Lady with a Hat” and “Man with an Earring” combine granite, iron, and found objects to create playful assemblage whose styling have a witty internal balance.

“Prelude,” by contrast, is a fond homage to geometric abstraction with the nifty trick that it’s composed of antique farm fencing wire and mica. As lively as anything imagined by Piet Mondrian, Heers' mica is sliced so thin, the fine-grained stone reflects a translucence.

One finds this same attention to detail in Heers' sculpture at his home, just west of Ann Arbor on Liberty near Wagner. These works are scattered about his ample property — many within sight of each other, but far enough away that each work can breathe within its own space. Heers' careful placement of his boulders and sculptures makes these enormous artworks appear quite comfortable in their setting.

The exceedingly handsome “Elements of Form,” for example, stands on a four-foot limestone apex with a polished stone triangle, cube, cone, and cylinder surrounding a centered polished stone ball; each element balanced on the wings of a wrought iron armature. The sculpture appears paradoxically stolid and airy; fitting its massive footing in contrast to these four elements of form whose opposite geometry works as a unity through Heers’ effort.

The same is also true of the masterly “Green Ash Tower.” This 42-foot-tall sculpture is as grounded as any artwork could ever be. Resembling a rough-hewn Midwestern Eiffel Tower, “Green Ash Tower” is made largely out of ash trees killed in the last decade by the invasive emerald ash borer on Heers’ property.

Working with blacksmith Scott Lankton and landscape architect Tom Rayer — as well as assorted family, neighbors, and friends — Heers has made an inspired artwork out of an ecological disaster. The monument’s logs bear what appear to be inspired curvilinear hieroglyphics, which are in actuality the markings carved by the borer larvae as they destroyed the trees. Combine this destruction with Heers single-minded reclamation of the wood for art and “Green Ash Tower” stands as tribute to an artistry that’s as heroic in scale as it is large in spirit.

“Wendel Heers: Site and Surround” continues through June 19 at the River Gallery, 120 South Main Street, Chelsea. Gallery hours are 11 a.m.-5 p.m. Tuesday-Friday, and 11 a.m.-8 p.m. Saturday. Guided tours of Heers' property, at 3893 West Liberty Street, are available from noon to 4 p.m. on Saturdays, June 12 and 19, and 1 to 3 p.m., Wednesdays, June 2 and 9. For information, call 734-433-0826.

John Carlos Cantú is a free-lance writer who reviews art for AnnArbor.com.