The Continental (and Other...) Divides

Drive west on US 58 from the Atlantic Ocean, parallel to the North Carolina border. You will cross over many divides, each defining the boundary of a watershed with streams and rivers flowing eastward to the Altantic Ocean. You will climb up the Blue Ridge at the Meadows of Dan and reach the crest - not at the Blue Ridge Parkway, but at the Patrick/Floyd county line. There, you cross the eastern Continental Divide.

The Eastern Continental Divide separates the waters flowing to the Atlantic from those flowing to the Gulf of Mexico. The airport at Blacksburg is on the Eastern Continental Divide. Some rain runs off it to the north, into Cedar Run and the North Fork of the Roanoke River and down to Albermarle-Pamlico Sound in North Carolina.

Runoff flowing to the south will drain into Stroubles Creek and then the New River. That water will flow through West Virginia, down the Ohio River, and go with the Mississippi River past New Orleans. After dropping a little bit of sediment from Montgomery County into the birdsfoot delta of the Mississippi River, the water from the Blacksburg Airport will finally enter the Gulf of Mexico.

A portion of Route 460 west of Virginia Tech marks the Eastern Continental Divide. Drive west from the campus towards West Virginia, climb to the crest of Brush Mountain, and when you come down off the mountain you will see an intersection with a sign for the US Forest Service recreation site at Pandapas Pond. That artificial pond marks the headwaters of Poverty Creek. It flows into Toms Creek and joins the New River at Whitethorne, roughly 500 feet lower in elevation.

in contrast, the rain that falls on the north side of US 460 (across the highway from Pandapas Pond) drops roughly 1,100 feet before reaching the James River. Forest Service Road 621 runs parallel to Craig Creek, north to Route 311 to New Castle, the county seat of Craig County. Craig Creek flows across Route 311 and ultimately into the James River, just upstream of Eagle Rock and halfway between Clifton Forge and Buchanan.

Craig Creek and Poverty Creek are both eroding away at the ridge which separates them, the ridge on which US 460 runs. At some point in the future, after Craig Creek carves its valley more than 500 feet deeper, it is likely to intercept the New River. The upper New River will then be diverted to flow into the James River and on to the Atlantic Ocean, rather than to the Gulf of Mexico. It is "stream piracy" when a stream is diverted into another watershed.

Don't assume the Eastern Continental Divide, or any divide, must be a crest as sharp as a knife's edge. Many of those driving on US 460 never realize they are driving on the Eastern Continental Divide just west of Blacksburg.

Similarly, the divide between the New River and the headwaters of the Tennessee River on US 11 is hard to recognize. The crest is at Rural Retreat, where the soft drink Dr. Pepper was invented, in Wythe County. It is the highest elevation on the original Virginia and Tennessee Railroad connecting Lynchburg and Knoxville, but such a gentle crest that even a bicyclist on Route 11 would have to be paying close attention to notice the exact location of the divide.

James River/Shenandoah River Divide Follow Route 11 (or Interstate 81) north to the divide between the Shenandoah and James Rivers at Steele's Tavern. It too is a subtle rise rather than a clear dividing line. In this case, the headwaters are etching away at the same bedrock, and the relative energy of the two streams is basically the same at this site. There's no clear ridgeline visible to identify the watershed boundaries; you have to notice which way the creeks are running to identify the divide in any particular spot. Coincidentally, Steele's Tavern is also the home of invention. The McCormick reaper was developed here, on the boundary of Augusta and Rockbridge counties and on the divide between the James and Shenandoah/Potomac watersheds. There is another Continental Divide in the Rocky Mountains, separating waters that flow to the Pacific Ocean vs. the Gulf of Mexico. The first Americans to cross that western continental divide were recent immigrants from Russia who had crossed the Bering land bridge. They were headed east, in small hunting and gathering groups. Roughly 15,000 years later, long after it had become routine for the local Native Americans to go back and forth over the Continental Divide in the Rockies, Lewis and Clark arrived. Lewis and Clark were the first Virginians to cross the western Continental Divide at Lemhi Pass on the current Montana/Idaho border, heading initially west to the Pacific Ocean and then crossing again on the way home. Those explorers were looking, in part, for the closest thing to a water-level passage to the Pacific in 1804-1806. Under the guidance of President Thomas Jefferson, the explorers followed the Missouri River upstream. They never realized that the topography of the Rockies would offer a far-better alternative at South Pass. Many emigrants travelling to the west coast, including the '49's rushing to California after the discovery of gold, crossed at South Pass in modern-day Wyoming. Cross it on Interstate 80, and you'll hardly notice the shift from going uphill to downhill. Of course, that's why emigrants with only 4 horses instead of a Sport Utility Vehicle thought it was such a great choice for traveling west.	Map source: Virginia Highway Map, 1998- 99

James River/Shenandoah River Divide

Follow Route 11 (or Interstate 81) north to the divide between the Shenandoah and James Rivers at Steele's Tavern. It too is a subtle rise rather than a clear dividing line. In this case, the headwaters are etching away at the same bedrock, and the relative energy of the two streams is basically the same at this site. There's no clear ridgeline visible to identify the watershed boundaries; you have to notice which way the creeks are running to identify the divide in any particular spot.

Coincidentally, Steele's Tavern is also the home of invention. The McCormick reaper was developed here, on the boundary of Augusta and Rockbridge counties and on the divide between the James and Shenandoah/Potomac watersheds.

There is another Continental Divide in the Rocky Mountains, separating waters that flow to the Pacific Ocean vs. the Gulf of Mexico. The first Americans to cross that western continental divide were recent immigrants from Russia who had crossed the Bering land bridge. They were headed east, in small hunting and gathering groups. Roughly 15,000 years later, long after it had become routine for the local Native Americans to go back and forth over the Continental Divide in the Rockies, Lewis and Clark arrived.

Lewis and Clark were the first Virginians to cross the western Continental Divide at Lemhi Pass on the current Montana/Idaho border, heading initially west to the Pacific Ocean and then crossing again on the way home. Those explorers were looking, in part, for the closest thing to a water-level passage to the Pacific in 1804-1806. Under the guidance of President Thomas Jefferson, the explorers followed the Missouri River upstream. They never realized that the topography of the Rockies would offer a far-better alternative at South Pass. Many emigrants travelling to the west coast, including the '49's rushing to California after the discovery of gold, crossed at South Pass in modern-day Wyoming. Cross it on Interstate 80, and you'll hardly notice the shift from going uphill to downhill. Of course, that's why emigrants with only 4 horses instead of a Sport Utility Vehicle thought it was such a great choice for traveling west.

Map source: Virginia Highway Map, 1998- 99