Even today, there is no direct interstate link between Salt Lake and Denver.
The highway has major junctions with U.S. Route 93 (US 93) in Kingman, the main highway connecting Phoenix and Las Vegas, Nevada, and I-17 in Flagstaff, the Interstate linking Phoenix and Flagstaff.
The second interstate link from Victoria to Adelaide (the oldest single-gauge inter-capital line dating from 1887) was converted from broad to standard gauge in 1995 enabling rail traffic from Victoria to access the rest of the nation without disruption.
A virus dropped at a cattle feed lot could wipe out a big part of the nation's food supply, they point out, while an attack on the dam at Lake McConaughy would cut off the main interstate linking New York and San Francisco and the biggest rail switching yard in the country.
But the agency and the corps seemed to raise doubts about those standards as well, saying in their new guidance today that "field staff should seek formal project-specific HQ approval prior to asserting jurisdiction over isolated non-navigable intrastate waters based on other types of interstate commerce links".
In the outlying north Bay Area, Interstate 10 links Anahuac and other communities nearby connecting them to Houston and the rest of the Bay Area.
Interstate 787 links Albany to Watervliet, Colonie, and Menands; by way of Route 7, I-787 connects to the Northway, offering Saratoga County residents a rather direct, albeit congested route to and from Albany during rush hour.
Interstate highways link Vermont with Massachusetts, New Hampshire, and Quebec province.
In Wisconsin, the rising Rock River prompted the closing of westbound Interstate 94, linking Milwaukee and Madison.
Interstate highways link Alabama's major population centres and connect the state to the national highway system.
