Areas of Natural and Scientific Interest

Areas of Natural and Scientific Interest (ANSI's) is an official designation by the provincial government and are areas of land and water that represent significant geological (earth science) and biological (life science) features.

Earth science ANSIs include areas that contain examples of rock, fossil and landform features in Ontario. These features are the result of billions of years of geological processes and landscape evolution.

Life science ANSIs are areas that contain examples of the many natural landscapes, communities, plants and animals found in the 14 natural regions of the province.

MNR identifies ANSIs that are 'provincially significant' by surveying regions and evaluating sites to decide which have the highest value for conservation, scientific study and education.

The location of Renfrew County's ANSIs can be found from the below maps or by using the Renfrew County GIS.

The ANSI's in Renfrew County are listed below. They can also be found as pink markers on the Renfrew County Special Natural Areas map. Please note that some ANSI's are publicly accessible, others are private with public access and a few more are private areas that require landowner permission to access.

Public ANSI's in Renfrew County

Centennial Lake

Centennial Lake is a 1563.1 ha Life Science Provincial ANSI, located in Greater Madawaska Township.

This area includes a provincially significant aquatic complex and uncommon plants and regionally significant upland forest. Red and white pine, red oak and red maple dominate the marble-based uplands. Along the south shore and north of Mackie Creek are wetlands, small bogs, bog forests and small peatlands. Upland plants contain uncommon southern species such as New Jersey tea, Kalm's grass, Cooper's milkvetch, reflected rock-cress, woodland sunflower and balsam sagwort. Shoreline and aquatic plants contain the rare grass-leaved water plantain, long-stemmed waterwort, as well as rich mixtures of pond weeds.

Map and Impressions


The Schooner-Fortune site shares many features of general landscape character with the Centennial Lake Nature Reserve and with the Schooner-Fortune Lakes site but maintains the largest Site District 5-11 representation of dry upland vegetation over marble and support aquatic systems which are unique within the site district. The Centennial Lake ANSI is surrounded by granite bedrock areas and functions as a lime-based partner, in ecological terms, to the Schooner Lakes areas to the south.

Greenbough Esker

Greenbough Esker is a 349.6 ha Life Science Provincial ANSI, located in the Township of Head, Clara and Maria. It is a prominent landscape feature of the upper Ottawa Valley that runs from south of Deux-Rivières to the vicinity of Wendigo Lake, roughly paralleling the Brent Road. The peatlands at its southern end support unique vegetation types and some uncommon to rare plant species. While the northern portion of the esker has been disturbed, the southern portion is largely undisturbed and has been recommended for protection as a Conservation Reserve.

Map and Impressions

Griffith Uplands

Griffith Uplands is a 567 ha Life Science Provincial ANSI, located in Greater Madawaska Township. This area protects a typical forest of trembling aspen, red oak and white pine on open bedrock clearings and rock barrens. Cedar swamps and wetlands are also found in the site. Much of the area is underlain by igneous rock, but a wide band of marble bedrock extends in a north-south direction through the Griffith Uplands, adding diversity to the site. Recreational use includes hunting, trapping, berry-picking, fishing, hiking, camping, ATV travel and snowmobiling. (click link for additional information)

Map and Impressions

Petawawa Terrace

Petawawa Terrace is a 214.4 ha Life Science Provincial ANSI, located in the town of Petawawa. The terrace includes intolerant coniferous upland forest of Jack Pine with White Pine dominates deep sand deposits on a terrace of marine sand at the west side of the site. Springs below this in a wet, cool, upland tolerant coniferous Eastern Hemlock woods and mixed intolerant upland forest (Balsam Fir, Trembling Aspen, White Pine, White Birch, White Spruce, Red Maple) support a variety of rare flora. Wet meadows, deciduous swamp thickets and emergent shores along the Ottawa River also contain aquatic associations not represented elsewhere in Site District 5-10. Tolerant lowland deciduous Sugar Maple - Red Maple - Black Ash forests are common along the rivershore though uncommon in the site district.

Map and Impressions

Pretty's Hill

Pretty's Hill is a 631.8 ha Earth Science Provincial ANSI, located in Petawawa Township. A terrific vantage point and scenic lookout are found atop Pretty's Hill, a dramatic kame moraine overlooking the Ottawa River south of Westmeath. To the southwest can be seen a large tract of Black Spruce, uncommon this far south, in the Westmeath Bog.

Map and Impressions

Private Renfrew County ANSI's - publicly accessible

Bonnechere Caves

Bonnechere Caves is a 7.4 ha Earth Science Provincial ANSI, located in North Algona Wilberforce Township. Bonnechere Caves ANSI is situated in a Paleozoic Outlier containing Middle Ordovician, Ottawa Formation jointed limestones. Holocene karst features such as caves, karst windows and stalactites developed in the limestone. This ANSI is considered to have the most extensive and finest cave system in Ontario.

Map and Impressions

Shaw Woods

Shaw Woods is a 111.2 ha Life Science Provincial ANSI, located in the township of Whitewater Region. The site is dominated by one of the few remaining remnants of original Ottawa Valley forest. This mature maple forest is notable for its cathedral-like canopy, reaching an average height of roughly 27 m. Many trees are over 30 m high, with diameters exceeding 1 m. Sugar maple has been recorded here at a height of 37 m, while shite birch reaches 33 m, white ash 35 m, white pine and basswood 31 m. The larger trees may reach ages of up to 250 years.

Map and Impressions

Private Renfrew County ANSI's - accessible with landowner permission

Davis Mills/Clay Hills

Davis Mills/Clay Hills is a 163.1 ha Earth Science Provincial ANSI, located in the township of Laurentian Valley. The ANSI contains Late Wisconsinan, North Bay Interstadial marine clays of the Champlain Sea. Water from Lake Algonquin drained through the ANSI cutting into the clays creating an unusual erosional landscape of solid clay hills. The clays are presently cut by the Indian River.

Map and Impressions

Green Lake Fen (Esker Bog)

Green Lake Fen (Esker Bog) is a 81.5 ha Life Science Regional ANSI, located in North Algona Wilberforce township. Green Lake Esker ANSI contains Late Wisconsinan series of esker ridges. The sinuous esker ridges stand in sharp contrast to the flat surface of the bog. The bog deposits are extensive, at least 11m thick. The internal structure of the eskers is evident in the road cut and in the many gravel pits.

Map and Impressions

Lapasse Pipeholes

Lapasse Pipeholes is a 25.6 ha Earth Science Regional ANSI, located in the township of Whitewater Region.

Map and Impressions

Lochwinnoch Landscape Scar

Lochwinnoch Landscape Scar is a 13 ha Earth Science Regional ANSI, located in Horton Township. A massive slumpage in the infamous Leda Clays of the area allowed a huge block of land to slip downslope. Leda Clays are unstable postglacial deposits of the Champlain Sea, which covered the lower Ottawa Valley about 10,000 years ago. When saturated with water they tend to slump. The scar is a prominent scalloped edge of an otherwise gentling rolling farm field.

Map and Impressions

McGrath Meltwater Channel

McGrath Meltwater Channel is a 42.6 ha Earth Science Regional ANSI, located in the township of Bonnechere Valley. McGrath Meltwater Channel ANSI contains a Late Wisconsinan meltwater channel, drumlinized till and a boulder lag deposit. The ANSI is located in a flat bottomed valley which was cut in drumlinized till by meltwaters issuing from a nearby ice front. Lag boulders occur in an abandoned channel.

Map and Impressions

Mink Lake Moraine

Milk Lake Moraine is a 19.9 ha Earth Science Regional ANSI, located in North Algona Township. Mink Lake Moraine ANSI contains a Late Wisconsinan moraine composed of sandy bouldery till with some sorted sands and gravels. There are several small moraine ridges running east-west and a classic example of a craig and tail feature. The moraine records one position of the withdrawing ice.

Map and Impressions