The Black Hills, Bear Lodge Mountains, and Devils Tower - Mountains and Plains: The Ecology of Wyoming Landscapes - page 280

Fig. 16.13. A mixed-grass prairie with black-tailed prairie
dogs in Wind cave national Park. the grass and other plants
are rather tall, an indication that the prairie dog population
was not large enough to keep up with plant growth at the
time this photo was taken. normally the rodents clip the
vegetation low, both for food and, presumably, to reduce the

amount of cover for predators. the pale green plant is fringed
sagewort, which, along with scarlet globemallow, is more
abundant around prairie dog mounds and in other disturbed
areas. Both are native species; there are no invasive plants
in this colony. Missing from grasslands such as this are the
carcasses of large mammals, as discussed in chapter 6.

stemming from climate warming, there is concern that
forage and water for the animals may be insufficient.
Management options are a reduction in herd size or
supplemental feeding and watering.
elk are another large herbivore in the park, though
they are seen less commonly and are not attracted to
prairie dog towns. in recent years their population has
exceeded the number that managers think the park can
sustain—at least under current climatic conditions—
without adverse effects on their habitat. to facilitate
achieving the goal of 400 elk, several hundred animals
were recently herded out of the park through gates in
what is now thought to be an elk-proof fence. Generally,
such fences should be avoided around national parks,
but they were constructed originally to prevent the
bison in Wind cave national Park from interbreeding
with cattle. the genetically “pure” bison population
in the park is highly valued by conservation biologists.
the original fences were effective for bison, but were

easily jumped by elk. At 7 feet, the new fences are taller.
there is still no hunting allowed in the park.
An entirely different concern was identified in the
condition report for Devils tower national Monument,
namely, a decline in riparian woodlands because of the
dam upstream on the Belle Fourche River, forming Key-
hole Reservoir. constructed in 1952, the dam reduced
the frequency and magnitude of flooding, which is
important for seedling establishment of plains cotton-
wood. the older trees are now dying faster than they
are being replaced (see chapter 4). Small trees have
been planted to replace them, but survival has been
poor. Also, the dam transformed a clear, fast-moving
river to a warm, sluggish stream with high turbidity.
the sediment load is partially attributable to livestock
grazing along the bank outside the monument. As
often noted, management activities outside a natural
area can have significant effects on the inside—and
vice versa.