Rockport Colony #2 Reservoir Report

Last Updated: December 5, 2025

Rockport Colony #2 is a private water resource located in Teton, Montana, specifically in PENDROY.


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Summary

Completed in 1960, this earth dam serves multiple purposes including fire protection, stock, and small fish pond usage. With a dam height of 15 feet and a storage capacity of 67 acre-feet, this structure plays a crucial role in the surrounding area's water management.

Owned and regulated by the state of Montana, Rockport Colony #2 is under the jurisdiction of the Department of Natural Resources and Conservation (DNRC). Despite its low hazard potential, the dam has not been rated for its condition assessment. With a primary purpose of fire protection and stock maintenance, the reservoir provides a reliable water source for the local community while also serving as a habitat for small fish.

Located along the South Fork Dry Fork Marias River, Rockport Colony #2 is a significant feature in the region's water infrastructure. With its strategic location, this earth dam stands as a testament to effective water resource management in the area, showcasing the importance of sustainable practices for climate and water enthusiasts alike.

Year Completed

1960

Dam Length

300

Dam Height

15

River Or Stream

S FORK DRY FORK MARIAS RIVER

Primary Dam Type

Earth

Hydraulic Height

15

Nid Storage

67

Hazard Potential

Low

Nid Height

15
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.

Hazard Potential Classification

High
Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.