BLACK RIVER HARBOR, MI - Thursday, May 29, 2008 - Yesterday our roving "unknown" photographer took the classic Black River Falls Tour, visiting Black River Harbor, Rainbow Falls, Gorge Falls, Potawatmi Falls, Sandstone Falls, Great Conglomerate Falls and the North Country Trail. He submitted the stunning photos above.

The marker text below gives a little history and a brief description of the geology of the area.

FRONTIER DAYS ON THE LOWER REACHES OF THE BLACK RIVER

Copper prospectors, excited by early successes in the Keweenaw Peninsula, worked the Black River prior to the 49'ers rush for California gold. Explorers, missionaries, and fur traders undoubtedly made brief visits to the harbor at the river mouth as early as the 17^th century.

William A. Burt, general land surveyor, made the survey in 1847 and 1848 of this immediate township. He found a wagon road in use by the Chippewa Mining Company. The road was on or about the same location as today's public road from the mouth of the Black River and south 5 ½ miles to Chippewa Hill (Copper Peak). This road passes the entrance to this National Forest recreation area.

Headquarters of the Chippewa Mining Company, at the foot of Chippewa Hill, consisted of eight buildings, one of which was a powder magazine. There were other copper mining claims, or "locations," tributary to the road.

Burt's field notes mention the "Chippeway" Mining Company location and road, waterfalls over Conglomerate, the cavern below Gorge Falls, abandoned mining efforts near the falls, existence of a good harbor for small craft, a wharf, and a storehouse at the mouth of the Black River. On August 12, 1947, he noted that "near the Company's location wheat was found ripe and very plump – also potatoes good for the season."

A survey of Black River copper prospecting was made in 1845 by agents of the Ordinance Office, War Department. Prospectors filed their claims with the War Department's Office in Ontonagon. The War Department reported that the Chippewa Mining Company commenced explorations in 1845 and "had prospects or raising much fine mineral by the opening of navigation the following spring." Other small traces of copper were found.

GEOLOGY OF THE BLACK RIVER

The Black River journeys about 30 horizontal miles and 1000 vertical feet from its origin in Wisconsin. It discharges into Lake Superior, two miles north and some 200 feet below the geology marker.

The river is almost as ancient as the hills it cuts through. It held its course through the centuries while the bedrock was gradually being raised and tilted. The tilting was part of mountain making. The remnants of the "mountain making" are the hills and valleys that have an east-west trend and make up the Gogebic Range.

Glaciers creeping down from the north helped wear down the mountains. The wasting away was accelerated by the work of water and ice, heat and cold, wind and rain. Only hills are left today.

The river flows over bedrock and gravel. Wearing away continues at a slow rate. The bedrock is composed of some of the oldest rocks known, the green stones and the granites. To the south are part of the cores of the earth. Most of the rocks were molten at one time. On this ancient base were deposited the younger sedimentary rocks. They were laid originally as flat beds as slates, quartzite, iron formation, conglomerates, and more slates. Part of these beds are inter-bedded with lava flows.

The sedimentary beds, under heat and pressure, became the rocks that were gradually tilted to make mountains. The edges of the beds can now be seen in many exposures, particularly along the river. Conglomerate is the major type of exposed rock in this part of the stream.

The resistance of harder layers of rock to vigorous stream erosion has caused many beautiful rapids and waterfalls. The commercial iron mines of the Gogebic Range are located in the iron ore deposit formations. Some of the slate formations are copper bearing and await the day when they become economic.