In 2022, Middlebury officially renamed the 60-acre parcel of land—previously referred to as “the bird sanctuary”—to be the Stephen C. Trombulak Nature Sanctuary, honoring Professor Emeritus Steve Trombulak. To learn more about Middlebury’s land stewardship and conservation efforts, click here.

General Description

The Trombulak Nature Sanctuary is located approximately 1 kilometer (less than a mile) south of the center of the Town of Middlebury on the west side of the Otter Creek. The Sanctuary is an approximately 24-hectare (60-acre) area between Otter Creek on the east and railroad tracks on the west; the Trail Around Middlebury (TAM) divides the sanctuary into northern and southern portions. The TAM is a public-access recreational path maintained by the Middlebury Area Land Trust, but the road is owned by Middlebury College and pre-dates the TAM.

The nature sanctuary is managed to conserve wildlife habitat, natural communities, wetlands functions and other ecosystem services. The area is primarily a place for nature, yet important human uses include teaching, research, nature connection and wildlife viewing.

Human History

Ever since the river formed after the post-glacial Lake Vermont and Champlain Sea receded, Otter Creek and the adjacent uplands and wetlands have been especially important in the region’s human history. The indigenous inhabitants, since time immemorial, have had and continue to have deep connection to the lands and waters. Abenaki and Mohicans seasonally hunted, gathered, fished, and lived in the area of lower Otter Creek, Onegigwtekw or Onegigwizibok being two of the names Abenaki use for this river in their homeland, Ndakinna. Whether Mohicans came this far up Otter Creek is unclear, but we can with certainty say that Abenaki stewardship of the Sanctuary lands and waters extends back thousands of years. Since these lands are nearly entirely wet floodplain it does not seem to be a likely Abenaki encampment or agricultural site, but rather a space of abundance for hunting, fishing and gathering. To our knowledge, no archaeological investigation has been conducted at the Sanctuary.

Early colonial settlers used Otter Creek as a primary travel route, as did the Abenaki. Upstream, near Three Mile Bridge, the earliest European settlers of Middlebury cleared forest and established farms. The exact history of land-clearing, farming and title transfers has not yet been explored for the Sanctuary. Middlebury College acquired the lands in 1916 as part of the Fertig Lot, a parcel over 40 hectares in extent. In addition to the Sanctuary, the Fertig Lot currently includes the college baseball and softball fields and the site of Porter Hospital. The entire lot appears to have been cleared and farmed prior to its acquisition by the college, and that farming likely continued until portions were developed into hospital and playing fields. At the Sanctuary itself, a large portion continued to be used for hay production into the 1990’s.

Aside from the farming lease, no records have been located that describe the college’s use of the land prior to 1986. A single groundwater test site, labeled as belonging to the Geology Department, was found in the forest near Otter Creek, but its history and use are unknown.

Since 1986, the Sanctuary has been used annually by faculty and students for various studies, especially on birds, mammals, trees, and wetlands. Over that time, a vegetation management plan was developed and implemented by Middlebury College Facilities Services to maintain grassland/shrubland habitat in the field. Selective logging, primarily single tree selection of red oak on the levee and higher terraces of floodplain forest, was conducted in the early 1990’s; no logging has occurred since.

Habitat Features

The 24 hectares of the Sanctuary include a variety of wetland natural community types that are now passively managed to allow natural dynamics to shape the composition and structure of the plants, animals, microbiota and soils. A 2-hectare area is maintained in a mix of grass and shrub cover to provide for habitat types that support birds (and other species) of conservation concern. This field was formerly larger, but succession by woody vegetation has been allowed over the past 20 years, and the far southern end now features an early successional forest that has been left to grow since 2001. The field management plan was developed by Audubon Vermont conservation biologists working on the Champlain Valley Bird Initiative.

The site is adapted to seasonal flooding when water crests over the Otter Creek banks; flooding occurs reliably in the spring and sometimes in the fall also. Forest natural communities are predominantly floodplain types, mostly Silver Maple-Ostrich Fern Floodplain Forest; a smaller section in the southwest is Mesic Clayplain Forest. Common tree species include silver and red maples, green and white ashes, American elm, and swamp white oak. Sugar maple, red oak and shagbark hickory are prominent in drier portions, and in the clayplain forest area white pine and trembling aspen occur as well. The forest understory features numerous species of shrubs, ferns and sedges.

A naturally non-forested portion of the Sanctuary features a dynamic natural community mosaic of shrub swamp, marsh, and open water. The mix and extent of different natural communities changes over time in response to beaver activity. This open wetland drains north via a small stream into Otter Creek. 

The managed field includes tall grasses, primarily reed canary-grass, wetland sedges and forbs, and shrubs. Gray birch saplings and small trees grow prolifically in unmowed areas, along with native and non-native shrubs. Among the natives are speckled alder, arrowwood, and willows. The most abundant non-native is Amur maple. Grassy, shrubby, and sapling filled areas are managed to provide a variety of bird habitats.


The Sanctuary is privately owned by Middlebury College. Members of the public are allowed to enter the area but only at their own risk and with the understanding that nothing present there is to be disturbed. This includes all natural features, equipment, and location markings. Collections of any kind are prohibited.

The Sanctuary can be accessed only from the Trail Around Middlebury (TAM) on the north. Travel through the field is along an infrequently mowed path through the wet meadow to a kiosk at the marked trailhead. From the kiosk, one can walk a forest trail and/or a short (0.2 miles) looped trail around the perimeter of early successional forest. The forest trail extends through clayplain and floodplain forest and provides viewing of a nonforested wetland complex of pond, marsh and shrub swamp, and Otter Creek. The forest trail is marked with blue blazes on trees and on wooden posts.

  • Forest Trail: 0.2 miles, starting at the kiosk at the head of the early successional forest loop, extending past the swamp on its western side, and ending on the west bank of the Otter Creek. This trail is generally well maintained. 
  • Swamp Trail Loop: 0.5 miles, heading north from the fourth marker post along the Forest Trail. This trail follows along a slightly elevated ridge or levee that creates high ground between the Otter Creek on the right and the swamp on the left.  The trail crosses a relatively deep channel on a wooden bridge before coming to a marker post (the only one along this trail other than at the start).  The trail forks at this marker. Veering to the left, the trail runs along the east side of the swamp. Depending on season, good views of the largest open portion of the swamp can be had at a number of locations, including one small spot where the low woody vegetation along the edge of the swamp is kept clear for wildlife viewing. The trail continues north from here for a short distance before it makes a sharp right-hand turn (watch for a double-blazed tree on the left for this turn), heads straight for the Otter Creek before turning south again, passing among several vernal pools before connecting with the main trail again at the marker post. The Swamp Trail Loop is well maintained from its start to the swamp, but is very poorly maintained from the swamp looping back to the marker post, and great attention needs to be paid to the tree blazes.


Satellite image of the Stephen C. Trombulak Nature Sanctuary at Middlebury College.

Natural History

Birds—The avifauna of the Sanctuary is the best studied group of animals at the site. Between 1986 and 2018, an intensive bird banding program was conducted each fall under the leadership of Steve Trombulak, Professor of Biology and Environmental Studies. Over that time, over 70 different species of bird were captured, banded, and released under the banding program managed by the U.S. Fish and Wildlife Service. The diversity of birds is high and includes representatives of 20 different families; impressive diversity was found among warblers (more than two-thirds of the species known from Vermont), sparrows, and thrushes. Numerous additional species have been observed but not captured, such as birds of prey (including Bald Eagles), waders, shorebirds, ducks, and geese.

Mammals—Many different species of mammal (14 of the approximately 50 species known in Vermont) have been observed here, ranging in size from white-tailed deer to short-tailed shrews. Particularly common are meadow voles, deer mice, white-footed mice, beaver, eastern chipmunks, gray squirrels, red squirrels, masked shrews, star-nosed moles, and raccoons, as well as white-tailed deer and short-tailed shrews. Many other mammal species are also likely to be present, such as red, and perhaps gray, foxes, mink, and various species of bats, but their secretive and nocturnal habits make them less easily observed.

Herps—Reptiles and amphibians have never been formally inventoried in the Sanctuary, but anecdotal observation has revealed the presence of garter and milk snakes, painted turtles, spring peepers, gray treefrogs, leopard frogs, and American toads. Other species are likely.

Natural Communities—Floodplain natural communities are a particularly noteworthy feature of the Sanctuary wetlands; the area has topography that allows for different flood levels and durations and thus different floodplain and “backwater” natural communities. The southern end, adjacent to Otter Creek is a fine example of a levee forest, Sugar Maple Floodplain Forest. As the elevation above the river descends the levee narrows, species that are more tolerant of longer flood duration and wetter soils predominate in a patchwork of Silver Maple-Ostrich Fern and Silver Maple-Sensitive Floodplain Forest types. Scattered throughout are small pockets of backwater swamp, too wet for tree growth. Some of these may function as vernal pools where salamanders and wood frogs reproduce; these low pockets contribute to a high level of herbaceous plant diversity. The open wetland area is a larger backwater wetland that includes Deep Broadleaf Marsh, Shallow Emergent Marsh, and Alder Shrub Swamp. The western part of the forested area, adjacent to the railroad tracks, is Mesic Clayplain Forest that reestablished in former pasture. That area does not flood, but it is wetland fed by groundwater and precipitation. White pine and trembling aspen are prominent trees, while the diversity of hardwood trees, such as swamp white oak, continues to reestablish and form a mid-successional forest growth. The field is maintained by periodic brush-hogging; were this management to stop, successional processes would lead to eventual development of floodplain and clayplain forest.

Plants—Many tree species occur in the Sanctuary. In the early successional forest gray birch and white pine are common. The floodplain forest features silver and red maples, with sugar maple, red oak and shagbark hickory only on the highest pieces of land. American elm, green and white ashes and swamp white oak can be seen throughout the woods, along with the small tree Musclewood. Among the shrubs are speckled alder and several species of dogwoods, as well as two rare shrubs—American hazelnut and the low creeping shrub, hairy honeysuckle (one of Vermont’s native honeysuckles). The diversity of herbaceous plants includes quite a few fern and sedge species, as well as woodland grasses and forbs such as groundnut and bedstraws. The rare and uncommon plant list is rounded out with Gray’s sedge, meadow horsetail and nodding trillium. The moist, fertile conditions of the forest are conducive to persistent and in places robust growth of poison-ivy. Invasive species are present in the Sanctuary, but are currently not prominent in the older forest areas. Invasives include the Eurasian honeysuckles, common buckthorn, Oriental bittersweet, poison parsnip, and garlic-mustard. In the shrubby field are native plants, such as willows, speckled alder, dogwoods and arrowwood. The invasive Amur maple is abundant in northern portions of the field. Reed canary-grass is the dominant herbaceous field plant, while rough goldenrod predominates among showy wetland plants such as common joe-pye-weed and blue vervain.

Franklin Environmental Center
531 College Street
Middlebury, VT 05753