Located about 10 km west of the town of Milk River, this large NA protects one of the few remaining area of native grassland.
[FP, MEDIUM DUE TO NUMBER OF REFERENCES]
- Map of the Area
- Other Information [optional, delete if empty]
- Site Statistics
- References and Further Reading

Map of the Area
Any maps and map views are for general information only. Do not rely on them for navigation or to determine legal boundaries.
Other Information
This natural area contains dense nesting bird-of-prey populations including ferruginous hawks, golden eagles and prairie falcons; rare yellow-bellied marmot and leopard frogs inhabit the site; rare fish include mottled sculpin, stonecat and finescale dace; rare plants in the area include prickly mild vetch, tufted hymenepappus and Carolina whitlow grass.
In addition to biodiversity this area protects important springs and wetlands as well as significant historical resources (tipi rings and medicine wheels).
This site lies in the Grassland Natural Region, Mixedgrass and Foothills FescueSub-region. Preserving these natural areas is difficult as it represents some of the best agricultural land in Alberta and thus difficult to find representative landscapes that have not been cultivated.

AWA Area of Concern. Ross Lake Natural Area and this NA both fall within a larger Alberta Wilderness Association (AWA) area of concern: the Milk River Ridge. Framed by two rivers, the Milk and St. Mary’s, this area is a stronghold for Alberta’s native grasslands. The area houses many rare and endangered fish, amphibians, birds and plants [1].
Water and Borders. The Milk River is susceptible to drought as it relies heavily on spring runoff for its natural flow. The Milk River’s low flow has been a source of contention for Southern Alberta’s agricultural producers, as many have advocated for damming or diversion to increase the Milk River’s flow. Damming could result in negative environmental impacts to the riparian habitat surrounding the Milk River. Under various treaties, the waters from both the St. Mary and Milk rivers are apportioned to irrigation at different rates [1].
2018 Proposed Expansion Fails to change the designation from a NA to a HR and increase the size by 3,173 hectares. Despite public support, the expansion and re-designation is not enacted [1].
Enclaves, Privately Owned. Within the NA are two one-section-sized areas excluded from the site. These are both privately owned based on the county landownership map [2].
HR or NA or Both? Protected Areas have specific classifications two of which are ‘Heritage Rangeland’ and ‘Natural Area’. So which of these two is this site? The answer is both and in limbo. It along with six other sites were given the NA designation in the late 1990’s during the Special Places 2000 program. The rationale was this was the ‘best fit’ for interim management until the legislation for the Heritage Rangeland class was pro- claimed. Management of these sites is a hybrid between a NA and HR until legislation is in place [3].
Site Statistics
Site Name | Twin River Heritage Rangeland |
Site Type | Natural Area |
Subtype | Order-in-council (OC) |
Natural Region(s) | Foothills Fescue; Mixedgrass |
O.C. No. (Land Ref. Manual) | 538/99 |
PASite ID (Map Ref #) | 586 |
Site # (Parks Website) | 508 |
Total Area | 19027.54 ha. (47017.57 ac.) |
Steward-Status | |
Recreation Activities | none noted |
IUCN | VI |
Operated By | Parks Division |
Notes and Comments |

References
The following links are provided as a courtesy but are not verified or endorsed by SAPAA. Clicking on the link will cause you to leave the SAPAA website. Primary source of information is: Information & Facilities – Twin River Heritage Rangeland Natural Area | Alberta Parks (All links accessed on 2023-02-14).
- Milk River Ridge – Alberta Wilderness Association
- “Heritage Rangeland” natural areas – Open Government (alberta.ca).
- County of Warner – Mapping (warnercounty.ca)
Further Reading
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