Round Top Butte
A Proposed National Natural Landmark
from Southwestern Oregon
Round Top Butte is
located near Medford, in
Jackson County
Round Top Butte is located in the National Natural
Landmark’s North Pacific Border Bio-physiographic
Region
Also located in
part of an
original “North
Pacific Interior
Valleys
Physiographic
Province”
Round Top Butte is an
example of the “Upland,
Un-Glaciated Grasslands
Subtheme”
Grasslands and oak
savannas dominated the
valleys and foothills south
of the Puget Sound in this
region.
As you can see here, they
have mostly been replaced
by agriculture, cities,
towns and forests, the
latter especially on the
valley margins.
Round Top Butte – Ownership and Management
The proposed
NNL is 747
acres.
It includes a 140
acre Preserve
owned by The
Nature
Conservancy,
and a 607 acre
Research
Natural Area
managed by the
Bureau of Land
Management
Round Top Butte is a mix of grasslands, oak and
pine savanna, chaparral and woodlands
The Round Top Butte, shown here, is located at the
north end of the site, on the Nature Conservancy
Preserve
The south side
of the butte
supports a dry
grassland
dominated by
bluebunch
wheatgrass
(Pseudoroegneria
spicata) and
Lemmon’s
needlegrass
(Achnatherum
lemmonii)
A mosaic of chaparral, grasslands and
Ponderosa pine woodlands is found at the
south end of the proposed NNL
Native grasslands dominated by California oatgrass
(Danthonia californica) characterize the grasslands and
savannas at Round Top Butte. The white flowered forb
is an endemic horkelia (Horkelia daucifolia).
The largest grasslands are a mix of native perennial and
introduced annual grasses. Introduced grasses have
replaced natives throughout the upland, unglaciated
grasslands in this region, primarily as a result of
inappropriate livestock grazing. Round Top Butte has the
largest concentrations of native grasslands in the region.
With fire suppression, woodlands become forests;
savannas become woodlands; and grasslands vanish
Round Top Butte is unusual in that fire can still be used
to maintain the natural diversity of the habitats.