Topography probably the most distinctive characteristic defining a physiographic province. Each physiographic province has a topographic character that is generally defined. This does not mean the topography is all the same; there can be variation. For instance, the Colorado Plateau has higher-elevation mesas with intermediate to lower elevation valleys. Geologically, these features are distinctive and similar. But the Colorado Plateau also has mountains - The San Juan Mountains - bordering on the southeast of the province. These mountains are all distinctive Tertiary volcanoes, some of relatively immense proportions. The only east-west mountain range in the United States is found on the northern boundary of the province. These are the Uinta Mountains. Rivers are typically in deep canyons; think Goose Necks of the San Juan.
A comparison with the Rocky Mountains shows the mountains and upland areas are largely supported by granite. The mountains are formed from granite ranges flanked by sedimentary rocks. Rivers are formed in steep, upland glaciated valleys.
At the eastern edge of the Rockies is seen the expansive Great Plains province, a place of completely different typography. The Great Plains province has flat, gentle, rolling typography, with grasslands and broad river valleys.
These are just some examples, without laboring the point. Each province has its own distinctive typography. A good place to look is the Cascade Ranges province. What is the distinctive topographic feature there? (Answer: Typically active volcanoes, such as Lassen Peak in California, or Mount Rainier, Washington, all consequent to the subduction of the Juan de Fuca tectonic plate.)
