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Ennis National Fish Hatchery
Mountain-Prairie Region
Graphic button showing the 8 state mountain prairie region

Ennis National Fish Hatchery

180 Fish Hatchery Road | Ennis, MT 59729
Hours: 7:30 am to 5 p.m.| Phone: (406) 682-4847 | Fax: (406) 682-7635 Email: Ennis@fws.gov

About the hatchery

Blaine Springs - It's the Water! | Ennis Investigations in Fish Culture | Species & Production | Youth Conservation Corps | Volunteer Program | Public Information | Open / Close All

  • Overiew photo of the Ennis National Fish Hatchery. Credit: USFWS.

    Overiew photo of the Ennis National Fish Hatchery. Credit: USFWS.

  • A Service employee inspects fish eggs produced at the Ennis National Fish Hatchery. Over twenty million eggs are produced each year. Credit: USFWS.

    A Service employee inspects fish eggs produced at the Ennis National Fish Hatchery. Over twenty million eggs are produced each year. Credit: USFWS.

About Us

The Ennis National Fish Hatchery (NFH) was authorized by Congress in May 1930, and started fish culture operations in July 1933. Ennis National Fish Hatchery is different from other hatcheries. Most hatcheries produce fish of various sizes and then stock these fish in public lakes and streams, providing anglers with hours of fishing fun. Ennis NFH, however, operates as a broodstock hatchery and is the largest facility in the Service’s National Broodstock Program. It is one of only two rainbow trout broodstock hatcheries in the nationwide federal hatchery system.

A broodstock hatchery specializes in rearing fish to adult size, then taking the eggs from those fish, incubating them, and shipping them to production hatcheries where they are hatched and the fish raised to stockable sizes. Ennis produces about 20 million rainbow trout eggs annually for research facilities, universities and federal, state and tribal hatcheries in 23 states. As a result of the Ennis Broodstock Program, economic benefits weigh-in at 5 million angler days, generating $50 million per year. To meet the trout production demands, Ennis NFH facilities include 38 hatchery tanks, 48 circular tanks, and 36 raceways.

The hatchery also produces 350,000 fingerling rainbow trout for the state of Montana which are stocked in Montana lakes and reservoirs. After 3 or 4 years, broodstock (the adult fish that provide eggs) are “retired” and stocked into public waters in Montana's urban and youth programs. Ennis NFH continues to be whirling disease free, with spring and raceway covers to ensure its disease-free status.


Blaine Springs – It’s the Water! »

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  • Photo of Blaine Springs. Credit: USFWS.

    Photo of Blaine Springs. Credit: USFWS.

  • Photo of an underground spring at Blaine Springs. Credit: USFWS.

    Photo of an underground spring at Blaine Springs. Credit: USFWS.

Sometime in the geologic past, disturbances in the earth’s crust created an area where pure, disease-free, clean water bubbled from the ground. Today, Blaine Springs flows at a rate of 15,000 gallons per minute. Imagine pouring 240,000 glasses of ice tea every minute. That is the amount of water that comes out of the ground at Blaine Springs 24 hours a day, every day of the year.

Blaine Springs is a very dependable water source. Only one decrease in flow was ever recorded, and that was in the spring of 1993 after several years of drought. April and May of that year resulted in abnormally large amounts of rainfall and the Spring resumed its normal flow. The water is a constant 54 degrees Fahrenheit, an ideal temperature to nurture trout. After passing through Ennis NFH, Blaine Springs water is used for irrigation by several ranches.


Ennis Investigations In Fish Culture »

  • Close up photo of fish eggs. Credit: USFWS.

    Close up photo of fish eggs. Credit: USFWS.

  • Egg sorting at Ennis National Fish Hatchery. Credit: USFWS.

    Egg sorting at Ennis National Fish Hatchery. Credit: USFWS.

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The following titles are unpublished data from various investigations in fish culture done by the staff at the Ennis National Fish Hatchery.

Spawning, Fertilization, Water Hardening, Incubation, Treatment of Rainbow Trout Eggs


Diet Tests


Nitrogen Gas Supersaturation


Fin Erosion and Fin Splitting


Spawning, Fertilization and Water Hardening of Artic Grayling Eggs


Radon Gas Removal at Ennis National Fish Hatchery


Species & Production »

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  • Rainbow Trout. Credit: USFWS.

    Rainbow Trout. Credit: USFWS.

  • Rainbow Trout. Credit: USFWS.

    Rainbow Trout. Credit: USFWS.

  • Hatchery employee working in Rainbow Trout area. Credit: USFWS.

    Hatchery employee working in Rainbow Trout area. Credit: USFWS.

  • A Rainbow Trout swims near the top of the water. Credit: USFWS.

    A Rainbow Trout swims near the top of the water. Credit: USFWS.

  • Rainbow Trout swimming. Credit: USFWS.

    Rainbow Trout swimming. Credit: USFWS.

  • Close up photo of Rainbow Trout swimming. Credit: USFWS.

    Close up photo of Rainbow Trout swimming. Credit: USFWS.

  • Birds eye view of Rainbow Trout at Ennish NFH. Credit: USFWS.

    Birds eye view of Rainbow Trout at Ennish NFH. Credit: USFWS.

  • Rainbow Trout fish eggs being transported. Credit: USFWS.

    Rainbow Trout fish eggs being transported. Credit: USFWS.

Species
Broodstock are adult fish that produce eggs and sperm. Seven different strains of rainbow trout broodstock are cultivated at Ennis National Fish Hatchery. The strains are named for the locations from which they came.

  • McConaughy (Nebraska)
  • Eagle Lake (California)
  • Shasta (California)
  • Erwin/Arlee Cross (Tennessee)
  • Fish Lake (Utah)
  • Arlee (Montana)
  • Harrison Lake (Montana)

Some of the eggs from each strain are hatched and reared at Ennis for future broodstock. They mature at 2 or 3 years of age and are kept for spawning another 2 or 3 years.Geneticists are hired periodically to monitor the genetic variability of the broodstock using a process called electrophoresis (identifying amino acids within the fish). When monitoring shows that genetic variability is deteriorating, eggs or sperm will be shipped to the Ennis National Fish Hatchery (NFH) from outside sources to restore genetic variability of the stock.

Some of the eggs from each strain are hatched and reared at Ennis for future broodstock. They mature at 2 or 3 years of age and are kept for spawning another 2 or 3 years.Geneticists are hired periodically to monitor the genetic variability of the broodstock using a process called electrophoresis (identifying amino acids within the fish). When monitoring shows that genetic variability is deteriorating, eggs or sperm will be shipped to the Ennis National Fish Hatchery (NFH) from outside sources to restore genetic variability of the stock.

Broodstock at Ennis NFH may grow 32 inches and weigh 25 pounds. Once the fish are no longer needed as broodstock, they are transported and released in kids ponds in Montana where young anglers test their skill at landing big fish.


  • Air spawning. Credit: USFWS.

    Air spawning. Credit: USFWS.

  • Spawning. Credit: USFWS.

    Spawning. Credit: USFWS.

  • Service employee rinsing eggs. Credit: USFWS.

    Service employee rinsing eggs. Credit: USFWS.

  • Service employee pouring eggs. Credit: USFWS.

    Service employee pouring eggs. Credit: USFWS.

  • Young Trout, also referred to as 'fry'. Credit: USFWS.

    Young Trout, also referred to as 'fry'. Credit: USFWS.

Spawning, Fertilizing, and Incubating Eggs
When a female is ready to release her eggs, a hypodermic needle connected to an oxygen bottle is inserted into the body cavity. Air pressure forces the eggs out of the body cavity into a pan. This process does not hurt the fish. Milt (a milky substance containing the sperm) from the male fish is mixed thoroughly with the eggs. Microscopic sperm cells in the milt have a long whip-like tail which propels them rapidly around the eggs. When a sperm cell enters the micropyle (a microscopic hole in the egg) it unites with the nucleus of the egg and fertilization is complete. Fertilization must take place very quickly because the sperm cell only lives about 30 seconds in water!

After fertilization, eggs are put in incubators where they continue to develop until Ennis NFH personnel can see the eyes of the tiny fish inside the egg. The eggs are then ready to be processed and shipped.


Eggs ready for shipping. Credit: USFWS.

Eggs ready for shipping. Credit: USFWS.

Transporting Fish Eggs
How would you like to be responsible for packing and shipping 20 million fish eggs every year? You would have to be very careful because the eggs are fragile!

First, it is necessary to separate live eggs from dead eggs. To do this, the eggs are poured into a sorting machine that uses optical sensing to separate the orange-colored live eggs from the white dead eggs. Usually about 5% - 8% of the eggs are white.

The live eggs are then packed into specially constructed trays. The trays are stacked in an insulated box topped with a tray containing crushed ice. The ice melts during shipping, keeping the eggs both cool and moist. Packed this way they can stay alive at least two days. Eggs are sent by express carrier and usually arrive at their destination within 36 hours.


Youth Conservation Corps »

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  • Photo of a sign for Ennis Montana. Ennis, Montana, home of Ennis National Fish Hatchery where trout outnumber people. Connie Keeler-Foster/USFWS, Ennis NFH.

    Sign for Ennis Montana. Ennis, Montana, home of Ennis National Fish Hatchery where trout outnumber people. Connie Keeler-Foster/USFWS, Ennis NFH.

  • YCC participants stop for a photo while working on a field project. Credit: USFWS.

    YCC participants stop for a photo while working on a field project. Credit: USFWS.

  • YCC participants working in the greenhouse. Credit: USFWS.

    YCC participants working in the greenhouse. Credit: USFWS.

  • YCC participants observing fish in a stream. Credit: USFWS.

    YCC participants observing fish in a stream. Credit: USFWS.

  • Earth Day at Ennis National Fish Hatchery. Credit: USFWS.

    Earth Day at Ennis National Fish Hatchery. Credit: USFWS.

Interested in spending a summer in Montana's beautiful Madison Valley?
For several years Ennis National Fish Hatchery has been providing a crew of local high school students the opportunity to work for a summer with the Youth Conservation Corps (YCC) Program at a U.S. Fish and Wildlife Service facility. The students work in all aspects of the hatchery and play an important role in day-to-day operations.

Students between the ages of 15 and 18 years of age may apply for summer employment. Applications may be obtained from Ennis National Fish Hatchery beginning February 1 and ending April 15. The summer-long program generally begins the second week of June and finishes sometime around the second week of August. Participants will earn the current minimum hourly wage. Work includes feeding fish, spawning fish, keeping up the grounds, and performing facililty maintenance. Students are supervised by hatchery staff.

The Ennis National Fish Hatchery summer YCC program is an excellent opportunity for students to experience working in the beautiful Madison Valley. The hatchery is located minutes away from the world famous Madison River and within an hours drive of Yellowstone Park.

Visit the Mountain-Prairie Region YCC Web Site


Ennnis Volunteer Program »

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Volunteers at Ennis Earth Day. Credit: USFWS.

Volunteers at Ennis Earth Day. Credit: USFWS.

For several years Ennis National Fish Hatchery (NFH) has been providing men, women, and students the opportunity to work as a volunteer at a U.S. Fish and Wildlife Hatchery. The volunteers work in all aspects of the hatchery and play an important role in day-to-day operations. College students looking for experience in fisheries, along with adventurous adults have been among those to volunteer at Ennis NFH.

Volunteer stints at the hatchery can last for various amounts of time and begin at several periods throughout the year. However, volunteers are most helpful during the winter months, at which time the spawning season is in full swing. Volunteers work along side hatchery staff to maintain the facilities and care for the fish. Specific work duties include feeding the fish, cleaning raceways, and constructing egg trays used in egg shipment. However, tasks will vary depending on the season. Much of the work is physically demanding. Volunteers are not paid a salary, though they are provided a food stipend that is sufficient to cover basic needs. In addition to the stipend, the hatchery also provides fully furnished living quarters at no expense.

The Ennis National Fish Hatchery volunteer program is an excellent opportunity to experience working in the beautiful Madison Valley. The hatchery is located minutes away from the world famous Madison River and within an hours drive of Yellowstone National Park.

The hatchery is located outside the small town of Ennis, Montana. Ennis is a friendly town which contains - among other stores - a grocery store, a medical clinic, a pharmacy, several restaurants, and a small movie theater.

Visit the Department of Interior Volunteer Web Site for more volunteer information and volunteer applications.


Public Information »

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Volunteers at Ennis Earth Day. Credit: USFWS.

Volunteers at Ennis Earth Day. Credit: USFWS.

Ennis National Fish Hatchery is located in Madison County, 12 miles southwest of Ennis, Montana, along the northeastern foothills of the Gravelly Range.

The hatchery is open 7 days a week from 7:30 a.m. - 5:00 p.m. Visitors are welcome to take a self-guided tour of our visitor center and walk through the hatchery building where eggs and small fish are reared. There is a kiosk in the parking lot with visitor information and tour directions. Families and groups are always welcome to visit our hatchery at your leisure. Guided tours for groups are available but please call to schedule one in advance. There is also a display raceway with rainbow, blue and albino trout that weigh up to 10 pounds!

With over 3,000 visitors annually, the dedicated staff at the hatchery will normally be available to answer your questions. Education programs/tours are provided for the public and school groups when scheduled in advance.

The visitor center, raceway, picnic tables, rest room and drinking fountains are accessible to people with disabilities. Contact Ennis NFH at (406) 682-4847 for additional information. For more information about Ennis, visit Ennis Chamber of Commerce Homepage.

The mission of the U.S. Fish and Wildlife Service is working with Others to conserve, protect, and enhance fish, wildlife, plants and their habitats for the continuing benefit of the American People.
Last modified: July 24, 2019
All Images Credit to and Courtesy of the U.S. Fish and Wildlife Service Unless Specified Otherwise.
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