Unified Interior Regions

USGS streamgagers make a low flow measurement on the San Pedro River at Charleston.

View of reattachment sandbar located near the Carbon Creek drainage on Colorado River (River Mile 65).  Photo is from the long-term sandbar monitoring remote camera time-series archives, and shows the sandbar two months after the 2008 Spring High Flow Event.

Sandbar on the Colorado River in Grand Canyon deposited by 2008 controlled flood. The river is flowing from left to right and the location is approximately 64 miles downstream from Lees Ferry, Arizona.

Sandbar on the Colorado River in Grand Canyon deposited by the 2008 controlled flood. The view is looking downstream and the location is approximately 65 miles downstream from Lees Ferry, Arizona.

As part of the assessment of the binational San Pedro aquifer, the effects of urbanization on runoff in ephemeral streams was studied. Ephemeral streams are those that flow in response to precipitation. Runoff in tributaries to the San Pedro River is important in understanding the water budget of the river. In addition, in arid watersheds such as the San Pedro, flow in

Exploring the colorful southern Colorado Plateau in 3-D

By Philip Stoffer, Geologist

Take a colorful tour with the help of 3-D photography through some of the region's highlights:

• A plethora of parklands- Petrified Forest, Chaco Canyon, Wupatki, Grand Canyon
• High desert climate changes, past, present, and

Drilling for mineral resources near Canyonlands National Park, Utah

Climate change combined with overlapping high-intensity land uses are likely to create conditions detrimental to the recreation economy, wildlife habitat, water availability and other resources in hyper-arid landscapes, or drylands, in the future, according to a paper published in Ecosphere

More mesquite were visible, and prickly pear had replaced cholla as the dominant cacti. (Mitchel P. McClaran).

Two ranging poles were placed near the positions of two sets of saguaros in order to determine their heights, and hence approximate ages. Most were established in the 1890s, after livestock grazing and the removal of fine fuels had begun in the area. Several small saguaros have become established since the fire; one is to the left of the left-hand ranging pole,

USGS employees measuring flood flows on Rillito River in Tucson, Arizona.

USGS employees taking flood measurements using an Acoustic Doppler Current Profiler.