Deadly bighorn pneumonia east and southeast of Missoula spreads still further.

Both upper and lower Rock Creek herds are now infected-

Worse, the terrain is too rough in lower Rock Creek to cull the herd.

It appears that over 400 bighorn are at risk. Well over a hundred have already be culled. Others have just died on their own.

Pneumonia confirmed in Upper Rock Creek bighorn sheep herd. By Rob Chaney. Missoulian

Update 2/3/10: I’ve put together maps showing the locations of the bighorn populations that have shown signs of pneumonia across the west with some close-up maps of the areas.  The green areas are where bighorns currently live and the red areas are those showing signs of pneumonia.  Ken Cole

Map of the sick bighorn populations in the west
Map of the sick bighorn populations in the west

Map of sick bighorn populations in Montana
Map of sick bighorn populations in Montana
Map of sick bighorn populations in Nevada
Map of sick bighorn populations in Nevada
Map of sick bighorn populations in Washington
Map of sick bighorn populations in Washington







  1. Nathan Hobbs Avatar

    You can really see the potential for the pandemic to spread with this map, what software and data sources did you use to create the map?

  2. Larry Thorngren Avatar

    These areas with diseased Bighorns need to be treated like a Hot Zone. I worked as an industrial x-ray technician at the INEEL long ago and my job involved crawling around in various atomic reactors to x-ray new welds. I very often was suited up in full protective gear (coveralls, breathing apparatus, booties etc.)to keep radioactive dirt off of and out of my body.
    The bacteria and viruses that cause disease in Bighorns are like radiation. You can’t see, smell, or feel them. Workers handling diseased bighorns, or even walking through the area, should be required to suit up and make sure that they are not helping distribute pathogens to disease free Bighorns. Wearing the same boots and clothing,and using the same vehicles that they used in the diseased area, have the potential to decimate western bighorn populations if used in disease free areas.

  3. Ken Cole Avatar

    I used Google Earth to make the maps but the layers for bighorn sheep were generated by the states.

  4. kelly packard Avatar
    kelly packard

    I spent 1990-1992 attending college in Butte, MT. I spent the winters watching the bighorns on the Lost Creek Trail winter range outside Anaconda. In the winter of 1990-1991, I video taped over 140 rams in one herd (band). Many of the rams were very mature with huge horns. I saw a few that looked diseased – swollen eyes. The next winter I only found 12 rams on the winter range. When the disease outbreak hit this herd it spread rapidly and took a hefty toll.

    If anyone is interested in watching bighorn rams, this winter range is very easy to access.

  5. Ralph Maughan Avatar

    Larry Thorngren,

    In other words, it might be kind of like foot and mouth disease.

  6. Ron Kearns Avatar
    Ron Kearns


    Very good job with Google Earth and the overlay imagery.

  7. Terri Avatar

    I am wondering why no one is targeting the deadly poisons being sprayed in our forests as the culprit to these diseases in our animals. Not only are the Rams infected with this lung disorder – pneumonia, we have the Chronic Wasting Disease infecting our Deer and Elk since the 80’s.

    Our pine trees are dying and this year the Aspen have a new disease that includes a small black worm and black spots. Fungus is also growing on surrounding plants.

    Look at the health of our citizens. Lung diseases are escalating as well as cancers. Notice the increase of oxygen tanks all around us.

    When DDT was sprayed and our Eagles were going extinct we knew why, and stopped the spraying. Tordon and 2-4-D – a form of Agent Orange has been sprayed for many years now and yet there aren’t any red flags being raised as it being the culprit of our diseased earth. All we have to do is consider VietNam before we throw Tordon and 2-4-D out as a major possibility.

    We must be experiencing what our soldiers experienced when they tried to get answers to why they and their children are suffering. The run-around.

    We wiped out the foliage in VietNam – but was that all we wiped out? What about the Vietnamese civilians? What about our soldiers? And now, what about us?

    In the name of killing weeds, what else are we killing?

    We need answers to these questions!


Dr. Ralph Maughan is professor emeritus of political science at Idaho State University. He was a Western Watersheds Project Board Member off and on for many years, and was also its President for several years. For a long time he produced Ralph Maughan’s Wolf Report. He was a founder of the Greater Yellowstone Coalition. He and Jackie Johnson Maughan wrote three editions of “Hiking Idaho.” He also wrote “Beyond the Tetons” and “Backpacking Wyoming’s Teton and Washakie Wilderness.” He created and is the administrator of The Wildlife News.

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Ralph Maughan