The old-timers were prone to say that the meadows result from the work of the heavers. The land was made swampy when the beavers built their dams. The beaver dens undermined the banks. This made the ground good for grass and willows, but not for trees.

The explanation is correct, but not complete. This result of the beavers work could he effective only when there was a conveniently wide stream flat. Why the flats were present is explained by geologic history. It is helpful to consider the rocks of the area and some events of the geologic past.

In the last twenty years or so it has become possible to measure the age of rocks by means of a "time clock" called radiometric dating. Therefore, I can cite some ages in years with reasonable confidence.

The oldest rocks of the region form a thick and widespread layered unit which geologists call the Belt Series. These rocks have been partly altered from their original sedimentary type. Common sedimentary rocks are stones formed of sand, silt. and clay piled by rivers into some kind of a basin of collection, such as a valley. lake, or ocean. The Belt Series was formed of sediment brought by unknown rivers into a very ancient sea. This occurred at an early period of the earth's history, because the rocks are assigned to a part of geologic time called the late pre-Cambrian. Their age is more than 600 million years; perhaps even nearing a billion years.

No fossils are found in them, because such living things as existed when they were formed were simple forms without sh∓mp;ls and skeletons. Soft parts of animals do not ordinarily fossilize. As yet. at this time, there were neither plants nor animals on land.

Good examples of the Belt Series rocks are found in many of the higher hills at the headwaters of the Potlatch and Palouse Rivers. They are characterized by layering. and commonly split in flat or wavy slabs. Excellent examples are seen on Ruby Creek above the Horse Ranch; on the East Fork of the Potlatch above Jackson Creek; and on Emerald Creek.

Almost all other rock units in the region belong to one or another kind of igneous body. "Igneous" means they formed from cooling of a molten rock substance. They vary in composition and also in their mode of development.

The melting occurred in the earth at a considerable depth. If the rocks solidified within the earth without reaching the surface. they are known as an "igneous intrusion." If the igneous material was ejected on the surface as a volcanic deposit or lava flow, it is called a volcanic rock or "extrusive."

The intrusions are represented by rocks of granitic type. They are not all alike in composition. and each type has a specific name; but the familiar name "graniter' serves fairly well for all. Generally they can be recognized simply by comparing them with the gray. greenish, or sometimes even pink-colored "granites" that serve as headstones in the cemeteries.

The granites form irregular bodies enclosed in the Belt Series rocks, which were there first, and acted as the "host" to the intrusion. They are found at the surface only where the overlying roof of the host rock has been eroded away. The intrusions evidently were formed near the periphery of a much larger intrusive body. known as the Idaho Batholith, which occupies Central Idaho. The intrusions occurred mainly in the Cretaceous Period of geologic time - the period popularly known as the "Age of Dinosaurs." Their age is about 130 to 150 million years.

When the granite intruded the Belt Series, the character of the sedimentary rocks was changed. This was the result of the heat and the chemistry of soaking solutions and mineral-bearing waters. Minerals such as mica, feldspar, quartz. and garnet were added to rocks that previously were mostly sandstone and shale. The product was a metamorphic rock (meaning "altered rock") of a type called gneiss.

In addition, certain actions of the mineral-bearing waters were responsible for introducing veins of metallic mineral deposits such as gold. silver, copper. and zinc. These may occur either in the metamorphic rocks or within the granite body.

Near the town of Bovill, granitic rocks are seen in the southeast face of the Big Rock Hill a little east of the old slaughter house location; along the East Fork of the Potlatch between Little Meadow and Frei Meadow; and in some small masses in highway banks on Ruby Creek. Large areas of deeply weathered, rotten granite occur in Neva Hill, and also on the way to Clarkia, near Keeler. This weathered granite looks like granular, yellow clay. A good outcrop of hard granite may be seen also on highway 95 on the divide between Moscow and Viola.

A second group of igneous rocks is the Potato Hill Volcanics. These are mostly a type called quartz latite. They apparently represent lave outpourings from a volcano. Possibly. also. they may represent the "neck" part of the volcano, which is the lava solidified in the throat of the volcano beneath the crater.

The volcanic material forms the entire mass of Potato Hill and Cherry Butte. An excellent cropping of the rock is uncovered in a railroad cut about a mile east of Deary. Boulders are tumbled below the grade and near the highway. An inconspicuous mass of rock occurs in a second area about a mile south of Bovill. along the highway and railroad near the road fork to Camp 7,

At one time, the Potato Hill Volcanics. were thought to he older than the granites. Now. geologists think they may be as young as Eocene (Vance and Shook, 43). This would mean an age of about 50 million years. Doubt on this could be settled if a radiometric date were obtained.

It appears that Potato Hill is the remaining part of a large volcano. Much of the original mountain probably more than half of it has been destroyed by erosion. If Cherry Butte is part of an opposing slope of the same volcanic pile, which seems likely. the volcano was a large one, indeed.

Another kind of volcanic rock of the region is known as the Columbia River Basalts. The basalts represent lavas spilled over an enormous area covering half of the State of Washington. part of Oregon, and some of Northern Idaho.

The extrusion of these happened during the middle part of the Tertiary Period of geologic history, about 6 million to perhaps 30 million years ago.

The basaltic lavas were much more than ordinarily fluid. The eruptions therefore did not commonly build the volcanic mountains that are the classic volcanoes. Instead, the fluid rock flowed quietly from fissures at various places. It spread sheet upon sheet during the long period of volcanism, and in this way filled the great Columbia Basin.

Stream systems formed and forests grew during periods when the volcanic activity temporarily ceased. Lakes formed and filled with sediment, only to have this sediment covered by new lava. Along the Potlatch below Juhaetta is an outcropping of shaley clay which contains fossils of semi-tropical plants such as fig and cypress.

The basalt filled the Columbia Basin. under a downwarping basin floor to a depth that at a central point, near Pasco. Washington. considerably exceeds 10.000 feet (Zietz et al.. 28). Spreading into Idaho, it flooded around the projecting spurs of mountains and back into valleys. It behaved very much like melted wax that is slowly poured, layer by layer, into a large irregular mold.

It spread up the Coeur d'Alene and the St. Manes River valleys. past the location of St. Manes. to the site of Clarkia. It spread up the Palouse above Pot-latch, to the vicinity of Harvard. It wrapped around Moscow Mountain. Steptoe Butte. Paradise Ridge and Tomer Butte, leaving these relatively as "islands" and "headlands;" and it then spilled back into the Potlatch Basin. Similarly, it wrapped around ridges extending from McGary Butte. and reached the location of Elk River.

The basalt is a dark, drab gray. Commonly it is fractured into columnar form, or into blocks stacked one on another in a columnar arrangement. such as would be obtained by piling blocks of wood one on another. Examples of the rock are found in road banks of the canyon near Troy; in canyonland south and west of Deary; near Kendrick and Juhaetta; in the Lewiston Hill. They are also seen in railroad cuts south of Bovill.

The extrusion of the Columbia River Basalt was a momentous event. The perched profile of the Palouse Country above the canyons. and the great. bench-like surface of the Columbia River Plateau would be missing from the landscape were it not for the basalt. And the meadows. as we know them, would never have developed.

The flows of basalt reaching the Bovill and Deary area were evidently late ones, because they are among the top layers of the stack. They buried a land surface formed of the three fundamental older rock units which are the Belt Series, granites, and Potato Hill Volcanics. As shown in drawing A, the valley of streams which were ancestors of the Potlatch, Palouse, and St. Manes Rivers were deeper than the present ones.

The movement of the flows was arrested by the hills. and the lava then cooled too much to flow further along the valleys. These things determined the edge of the basalt terrane. And since the plateau was an effective dam across the streams, only one thing was possible: the remaining valleys heyond this edge became ponds and lakes. And into these was washed the sediment from the hills - some gravel. and a good deal of sand and clay, until they were filled. A large lake was in the vicinity of Bovill.

Some of the clay deposits formed at this time are being mined today just west of Bovill. They are seen along the highway west of town. Related deposits occur in the Purdue and Collins area, and are found along the road which crosses the summit from Bovill into the Potlatch East Fork. The sediment infill was not complete until it reached the level of the plateau. In following along or near the margin of the basalt it is often difficult to tell, without seeing the rock. if one is on the basalt, or the sediment infill. or perhaps even a half-buried ridge of older material.

Make this test. Go to a relatively high vantage point - the cemetery hill at Bovill or one of the higher summits along the way between Bovill and Troy. If visibility is good from the point you choose. you will see a profile of hilltops at the same level. Allowing a little for very deep soils, this is the summit level of the basalt plateau and of the infill behind it. Valleys today are eroded below the summit level. And hifltops well above this level represent older rock.

Even a better view' can be obtained. Climb to a high vantage point such as Potato Hill or McGary Butte. From such a position. the even surface of the plateau and shallow valleys that cross it - also the hills of older rock standing above the plateau - can be easily distinguished.

There is an interesting difference in landform between the hills of the Pa-louse area (for example. around Moscow and Pullman) and the hills at Bovill. In the Palouse region the hills are gracefully sculptured by wind (Fryxell, 8). The deep, rich soils of this sector are a particular type of deposit called "bess." This soil was blown in great clouds - choking dust storms - across central Washington during a period of the Pleistocene (ice age) glaciation. The dust evidently came from deposits of a dry lake bed in the "Big Bend" of the Columbia River Valley. Much of the powdery rock material may have washed into the former lake when grinding glaciers moved into the valley much farther north. From what I have read. this drift of dust began well over 100,000 years ago. Probably most of the soil deposits were formed before the final glacial retreat 20.000 years ago. because west of Spokane, soils were eroded cleanly to the underlying rock by the melt-water of these glaciers. As seen today around Cheney and southwestward toward the Palouse, Snake, and Columbia Rivers, this eroded area is known as the "channeled scabland."

The bess soil did not reach the Bovill area in equal amount because the wind-blown material was filtered out by grass. and then the trees and the spurs of mountains. It piled up deeply in the belt of grassland west of Moscow. A much larger percentage of the soil at Deary and Bovill is residual.

The edge of the basaltic plateau. extending to the Bovill area. marks the line of the largest meadows. The soft sediments behind the basaltic dam were I easily eroded, and this provided the broad valley floors adapted to meadowland. But a few flat areas are present in other places, too. It appears that hardness differences were present in the basalt itself. Perhaps these relatively 'soft' areas represent places where sediment layers were enclosed between lava flows, or where the lavas thinned over old ridge tops. And even in the areas of metamorphic and granite terranes are local streamflats.

A classification is possible.

(1) Meadows largely or wholly within the sedimentary infill: the Warren meadow and other meadows at Bovill, extending to Collins; Moose Meadow, and Erickson, Bronson, and Shea Meadows.
(2) Meadows along the basalt margin, where the lava made contact with older rocks; The Horse Ranch; Jim McGary Meadow, Oviatt and Round Meadows.
(3) Meadows partly influenced by infill, and partly by the configuration of older rocks; Little Meadow and Frei Meadow.
(4) Meadows entirely within the basalt small ones on Pine Creek and Bear Creek near Deary; partly in the basalt; Hog Meadow and Eustler Meadow.
(5) Meadows entirelv within older rocks; Badger Meadow; the meadows on Emerald Creek; Graves and Smith Meadows near Harvard. Most of the meadows above Harvard and Clarkia, and near Elk River lie mainly upstream from confining basalt.

So the meadows can be credited to the extrusion of lavas. They can be credited to the beaver. Or, for those not curious about the natural way of things there is another way to say it, and still true. God made them.