Colorado BHA Bighorn Observation Volunteers Needed

Project Lead: SW Colorado BHA Board Member, Dan Parkinson - [email protected] and 970-759-0545

To help the Forest Service and Colorado Parks and Wildlife record observations of bighorns in the Weminuche Wilderness, especially in or near active domestic sheep grazing allotments. And to give members a chance to get into the wild, get in shape and share some great memories!

During domestic sheep grazing season – July 1 through September 30, 2017. Choose any date that works for you, your friends and family – be it part of a camping vacation, a scouting trip or a special trip just for the challenge of finding bighorns! The first year of this effort is loosely organized to encourage folks to get out there. We will develop more targeted efforts next year.

In a part of the Weminuche Wilderness area north and east of Durango, identified in the maps below. Researchers are particularly interested in looking for bighorns at the northern and eastern boundaries of the area made up of the three active grazing allotments, but any location in or near (within a few miles) the allotments will be helpful. If you are planning a trip to another area in the Weminuche, any observations of bighorns are also welcome. Maps of each of the areas of interest can be found here:

Endlich Mesa Map - Endlich Mesa Grazing Schedule

Tank Creek Map - Tank Creek Grazing Schedule

Virginia Gulch - Virginia Gulch Grazing Schedule


First, check out a map of the Weminuche Wilderness and select an area that you would like to visit or explore. Prepare for an adventure in the wilderness. You will need good backpacking gear including rain gear, maps, GPS, and binoculars or spotting scope. The area is spectacular, wild and rugged. Be prepared for afternoon thunderstorms and some cold temperatures.  Above all, be safe.

If you want to look for bighorns near the active domestic sheep grazing allotments (BHA encourages you to do so) you will need to review the Grazing Allotment Maps above and the grazing rotation schedules above for the allotments.  Each allotment will have a band of sheep (approx. 750 ewes and their lambs for a total of about 1500 to 2000 sheep) and one herder.  The maps show the boundaries of the allotments and pasture and camp locations. The rotation schedules show the dates the pastures and camps will be in use. 

Plan your hiking/backpacking and camping schedule according to your desired destination and route taking into account the presence of domestic sheep in the area. See background information below for how to interact with sheep and sheep dogs on the allotments.

To report observations:

Download the Forest Service reporting form and reporting instructions to get an idea of the information requested by the Forest Service. Use a small pocket spiral notebook that is easy to carry and keep dry in the field. When looking for bighorns, use maps and GPS to verify your location and observation points. Please carefully note the date, time, location (drainage, mountain or ridge and GPS coordinates) for each observation location. Photos with GPS locations are especially helpful. If a bighorn is sighted please attempt to determine the sex and age based on the information provided on the reporting form.

Any bighorn sightings within an active allotment or within a mile or so of any of the active allotments should be reported immediately to the Forest Service and CPW, preferably with photos and GPS coordinates. That means as soon as you have a cell signal, call, text or email the officials and let them know this is high priority information!

Likewise, if you notice stray domestic sheep that are clearly separated from their bands please note their locations and report immediately to the officials noted below.

CO Parks and Wildlife
Brad Weinmeister, Terrestrial Biologist, Durango Area Office - 970-375-6714
[email protected]

Forest Service
Matt Janowiak, Columbine District Ranger, Bayfield, CO - 970-884-2512
[email protected]

Chris Schultz, Columbine District Wildlife Biologist - 970-884-1407
[email protected]

Jared Whitmer, Columbine District Range Staff - 970-884-1416 cell 970-903-4473
[email protected]

CO BHA Southwest Regional Director
Dan Parkinson DVM, Durango 970-759-0545 - [email protected]

After your trip, report all of your observations and time spent in the field by either completing the FS reporting form or simply fill out the BHA online survey form here! If you use the FS reporting form you can send a digital copy or hard copy to BHA Southwest Director Dan Parkinson. BHA will compile all the surveys and return them to the Forest Service at the end of September. Please note that all observation information is important – even if you don’t see bighorns, the Forest Service and CPW needs that data too.

Background on Weminuche Bighorns:

Historically, bighorn sheep were once among the most abundant wild ungulates in the American West. Population estimates range from 1.5 to 2 million at the onset of the 19th century. Bighorn populations declined with westward expansion of human populations because of market hunting, introduction of domestic sheep and overgrazing of rangelands.

Aggressive restoration and protection efforts have allowed populations to grow in the West from an estimated 25,000 in 1955 to 70,000 now. Growth in population in Colorado reflects these efforts, increasing similarly from an estimated 2,000 in 1955 to 7,000 now. Yet in recent years, bighorn population growth has stagnated across the West despite continued restoration efforts.

Current scientific consensus is that bighorn populations fail to thrive in large measure because of recurrent herd-level respiratory disease outbreaks associated with exposure to domestic sheep. According to a joint issue statement of The Wildlife Society and the American Association of Wildlife Veterinarians released in March 2015, “... it is now apparent that disease transmission from domestic sheep to wild sheep is a significant risk factor for the conservation and restoration of wild sheep populations,” and “effective separation of domestic sheep from wild sheep is the only currently available management solution for preventing or minimizing disease transmission.”

Weminuche bighorns are listed by the Forest Service as a sensitive species, meaning there is concern for their long-term viability. The Weminuche bighorn population numbers about 425 animals and is designated as a highly valued “Tier 1” population because it is believed to be one of only three herds statewide that have received little or no augmentation. That means these are true native bighorns, and as such, they represent an important historic gene pool for the San Juan Mountains and for the state.

The Vallecito Creek herd (GMU S28), which summers nearest the current active grazing allotments, has struggled to maintain viability and currently numbers only about 70 members. This herd is most at risk for exposure to domestic sheep, and because it is interconnected with the GMU S15 and GMU S16 herds, a disease outbreak in the Vallecito herd could easily spread to the greater meta-population, resulting in a serious health threat to all of the highly-valued bighorns on the Weminuche Landscape.

Young bighorn rams and ewes often wander in historic home ranges in search of new grazing or breeding opportunities. Foray distances of a few miles to 20-30 miles have been recorded. Bighorns are naturally attracted to domestic sheep and may mingle with them resulting in exposure to pathogens that can cause. Contact between domestic sheep and bighorns results in consistently deadly results for the exposed bighorns. As noted in a Durango Herald article (Nov. 30, 2016), bighorns known to be exposed to domestic sheep are killed by CPW staff in a desperate effort to prevent further disease spread. Exposed bighorns that manage to return to herds may spread diseases that cause acute all-age die-offs or negatively impact lamb survival for decades.

The Forest Service is responsible for managing bighorn habitat and livestock grazing on the Weminuche Landscape. Currently the Forest Service has delayed its final decision on the Weminuche Grazing Analysis pending further review of data being collected now. Six bighorns from the Vallecito Creek Herd (S28) were captured in early 2017, fitted with GPS collars and released. Blood samples were also collected for disease screening and analysis of those sample results are pending. GPS data will help researchers note the movements of the six collared bighorns – possibly near the active allotments. A final decision will likely be made based on this new information and on input from bighorn/domestic sheep working groups – locally and statewide.

There have been very few sightings of bighorns in the allotments (most unverified) and the permitee claims to have never seen a bighorn in some 40 years on the allotments even though the allotments are in historic bighorn home range. CO BHA hopes to help the Forest Service and CPW obtain more information about foraying bighorns by putting some BHA “boots on the ground” observers in and near the allotments. Verified sightings of foraying bighorns in or near active allotments, although perhaps unlikely because of the size of the country and the small number of bighorns in the area, will be taken seriously and will trigger necessary and required actions by the Forest Service, CPW and the permittee. CO BHA thanks all volunteers in this endeavor

Contact with domestic sheep:
Our goal is to get our members and other interested individuals out in the wilderness for enjoyment and a chance to be of assistance to the Forest Service in gathering information about bighorn activity in or near active sheep allotments. Please be respectful of the permitee’s livestock, livestock protection dogs and herders.
If you come in contact with domestic sheep and their livestock protection dogs:

• Watch for livestock protection dogs near sheep (usually large, white or tan dogs).
• Remain calm if a livestock protection dog approaches you.
• Verbally tell the dog “go back to the sheep” or say “no” in a firm voice.
• Keep your distance and choose the least disruptive route around the flock.
• Keep your dog leashed.

Do Not
• Chase or harass the sheep or the livestock protection dogs.
• Make quick, threatening movements toward the sheep or dogs.
• Try to outrun the livestock protection dogs.
• Attempt to befriend, pet or feed the dogs.
• Allow your dog to run towards or harass the sheep.
• Mistake a livestock protection dog as lost and take it with you.

Weminuche Wilderness information

Living with livestock protection dogs

Bighorn biology and viewing tips

Bighorn respiratory disease

About Dan Parkinson

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