Padlock No. 1 A Five Mile

Padlock No. 1 A Five Mile is an earth dam located in Sheridan County, Wyoming, built in 1961. It carries a High hazard potential classification and has a fair condition assessment.

About Padlock No. 1 A Five Mile

The primary purpose of Padlock No. 1 A Five Mile is irrigation. The dam stores and diverts water for agricultural irrigation, supporting farming operations in the surrounding area. The dam is owned by Padlock Ranch Company, Inc (private). It impounds the Five Mile Creek near Ranchester.

The dam stands 40 feet tall and stretches 1,228 feet across, creates a reservoir covering 59 acres, has a maximum storage capacity of 960 acre-feet, and collects water from a drainage area of 13 square miles. Completed in 1961, the structure is well into its service life at over 50 years old.

This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. Its condition is rated fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 05/21/2025.

At 40 feet, this dam is taller than 87% of dams nationwide.

Living Downstream

If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Wyoming dam safety program can provide more specific information about emergency planning for this structure.

Search for dams near your address to see all dams in your area with hazard classifications and safety data.

High HazardFair ConditionEmergency Action Plan: Yes

Location

StateWyoming
CountySheridan
Nearest CityRanchester
River/StreamFive Mile Creek
Coordinates44.95060, -107.25100

Physical Characteristics

Dam TypeEarth
NID Height40 ft
Dam Height36 ft
Dam Length1,228 ft
Year Completed1961 (65 years old)

Storage & Hydraulics

NID Storage960 acre-ft
Max Storage960 acre-ft
Normal Storage536 acre-ft
Surface Area59 acres
Drainage Area13 sq mi
Max Discharge8,561 cfs
Spillway TypeUncontrolled

Ownership & Safety

PurposeIrrigation
OwnerPADLOCK RANCH COMPANY, INC
Owner TypePrivate
Hazard ClassificationHigh
Condition AssessmentFair
Last Inspection05/21/2025
Emergency Action PlanYes

Identifiers

NID IDWY00659
Federal IDWY00659
More InfoState Dam Safety Program

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