by Daniel B. Botkin, originally published by Perigee Books, a division of Penguin/Putnam, 1999.

I have decided to share this book with the readers of my website, and I am going to present the entire book here, one chapter at a time, with a new chapter appearing each week.  There are more than 40 chapters.  If you follow along and read all of them, you will learn about the entire Missouri River as seen by Lewis and Clark at the beginning of the 19th century, and as I visited it during the 1990s to see what they had seen, and to learn how the countryside had changed.  I hope you enjoy it and find it rewarding.

- Daniel B. Botkin

All of the chapters published thus far can be found in the Passage of Discovery category. Please note that they are listed in reverse order of date posted.

More books by Daniel Botkin are available for purchase from the Center For the Study Of the Environment bookstore.

5. Arrow Rock State Park: Cottonwoods and the Resiliency of Life

Arrow Rock is reached most easily from Interstate 70.  Take this interstate about 30 miles west of Columbia and turn north on Route 41, and follow this until you reach Main Street of Arrow Rock, which you take east.  To reach Arrow Rock State Park continue east to the end of Main Street, then turn right and follow the road as it winds around and down a small hill and passes over a small stream.  The road continues up the hill to the park.

While the Missouri River was treacherous, it also created a well-watered and fertile bottomland where trees adapted to these conditions grew in great abundance.   On June 9, 1804, Clark wrote that they passed a place called “Praire of Arrows” which was below a bluff called “arrow rock” and where there was a stream called the “Creek of Arrows” flowing into the Missouri. Clark observed a “Delghtfull land” on the south side of the river.  The next day he noted that they “passed a part of the River that the banks are falling in takeing with them large trees of Cotton woods which is the Common groth in the Bottom Subject to the Flud.”

The bottomlands were full of cottonwoods, and these came and went at the will of the river, sprouting after a flood, dying when the current cut the soil out from under them.  We saw these same natural processes working at the same location, as we stood on a bluff overlooking Arrow Creek and the Missouri River.   After the time of the expedition, Arrow Rock developed as a crossing point on the Missouri River because Arrow Creek provided a way up and over the steep bluffs.  The Santa Fe Trail, which originates in Independence, Missouri, came this way.  This charming, small town blossomed briefly.  Now a small village of about 70 residents, it is registered as a National Historic Landmark.

We visited Arrow Rock on a beautiful spring day.  We walked down the main street through the town, past pleasant, well maintained houses, surrounded by shade trees and blossoming redbuds, some of the houses converted to Bed and Breakfast hotels, past a summer stock theater well known in the region.  Stores on the main street had wooden sidewalks and wooden porch-fronts, like a movie set western frontier town.  Here the movie Tom Sawyer was made years ago, the local people told us.  Walking through Arrow Rock was like walking into the past and into the perfect image of small town America.  It made us aware of how villages waxed and waned, with just a few, like Arrow Rock, maintained as reminders of the past.

At the foot of main street we turned right and followed the road down a short slope.  In a short time, we reached Arrow Rock State Park, with its large, manicured lawn of playing fields and a few trees, oaks and other upland species.  The park stood on the edge of the bluff, providing a magnificent view of the Missouri River.  Below us flowed the Creek of Arrows, much as Clark had described it.

Beyond the creek and far below us was a vast field of young cottonwoods, light green against the black bottomland soil. Beyond the first field of trees was a wide expanse of open soil and then another field of cottonwoods mixed with willows. In the middle distance were the levees along the channelized Missouri River, and then the main channel flowed – as straight as an arrow, as straight as Main Street – reflecting the blue of the sky.  In the distance, limestone bluffs could be seen.

The day before, Jim Milligan, fisheries biologist for the U.S. Fish and Wildlife Service and the Big Muddy National Fish and Wildlife Refuge, had told me that hundreds of acres of young cottonwoods had sprouted up on former agricultural lands after the 1993 flood, creating stands so dense they were almost impossible to walk through now and, if you succeeded, hard to keep your sense of direction unless the sun shown brightly.  Now these trees were five years old.  Remarkably, some were 20 and 25 feet high and up to five inches – as thick as a wrist – in diameter.   I had seen trees that had grown that fast on only two other occasions. Once on the Tanana River outside of Fairbanks, Alaska where, in a similar situation, on sandbars on the floodplain, balsam poplar, a relative of these cottonwoods, had also grown five feet a year.  The other was in Costa Rica where we went to the tropical rain forests with a local forestry expert.  We ate lunch under several balsa trees about 30 feet high, and he told us that those trees had sprouted five years before.

Under good conditions, trees of the upland forests of Missouri and the states to the east – like the oaks growing near us on the top of the bluff in the woods bordering Arrow Rock State Park – grow a foot or maybe two taller, and a half inch in diameter a year.  In a poor year upland trees, especially those adapted to the deep shade of older forests, increase in diameter hardly at all, a hair width, just wide enough so you can see there was a growth ring when you look at a stump.  Some trees, including some of the oaks, can persist for years with this kind of small growth.  Cottonwood is a fast growing tree characteristic of what ecologists call the early successional stage in the development of forest — the time soon after a disturbance, like the 1993 flood, when light, water and nutrient elements are in great abundance and there is little competition.  Willows are much the same, germinating and sprouting on newly formed floodplain soils.  Sometimes the willows come in first, especially on the coarser soils of sandbars, followed by cottonwoods.  Sometimes, as in our view, the cottonwoods sprout immediately, especially on the heavier soils.  Cottonwood is also the dominant species in what appear to be mature bottomland forests on the Missouri River.

Lewis recognized this process of the natural change in dominant species.

On June 14, 1804, a little father upriver from Arrow Rock and toward Kansas City, Lewis gathered a sample of the narrow leaf willow which he noted “is invariably the first which makes it’s appearance on the newly made Lands on the borders of the Mississippi and Missouri.”  These, he wrote, “grow remarkably close and in some instances so much so that they form a thicket almost impenetrable.”

Lewis also observed that, once the trees were rooted, they helped build up the floodplain soil.  “The points of land which are forming all ways become eddies when overflown in high water,” he wrote.  “These willows obstruct the force of water and makes it more still which causes the mud and sand to be deposited in greater quantities.”  Lewis added that “the willow is not attal imbarrased or injured by this inundation, but (the moment the water subsides) puts forth an innumerable quantity of small fibrous roots from every part of its trunk near the surface of the water which further serve to collect the mud.”

He also observed that the trees thinned themselves over time. “As the willow increases in size and the land get higher (and more dry) by the annul inundations of the river, the weeker plants decline dye and give place to the cotton-wood which is it’s ordinary successor, and these last in their turn also thin themselves as they become larger in a similar manner and leave the ground open for the admission of other forest trees and under brush….”

This self-thinning was happening already below us on Jameson Island.  The faster growing trees shaded out the slower growing ones, and the slower growing ones died.  The dead organic material from these thinned trees improved the already rich soil.  The cottonwoods and willows were a clear example of life’s great productivity and its ability to restore itself when conditions were right.

Floodplain forests have declined greatly since the time of Lewis and Clark.   These forests covered three quarters the Missouri River floodplain in 1826, but only 13 percent by 1972.   During that time, clearing the land for farming was a major cause of this decrease.  Land in crops increased from 18 percent to 83 percent of the floodplain lands.  But channelization also had its effect.  Sprouting and survival of cottonwoods and willows declined greatly because of the reduction in spring flooding.  The habitat had been changed and was no longer available or suitable to these trees.

The view from Arrow Rock State Park illustrated a general rule about life: Most species do well as long as their habitats are in good condition.  It is better to have a small population in a good habitat than a large population in a poor habitat.  And here the habitat for cottonwoods was near to perfect – a floodplain whose soil was just renewed, laid bare of other vegetation that could compete with the cottonwood sprouts, which do poorly when shaded by other trees.

Jim Milligan said that one of the farmers along the river valley, seeing the great productivity of the cottonwoods since the flood, is using these as crops.  A five-year-old tree that was 25 feet high and five inches in diameter could be sold for fiber if a timber processing plant were near enough to make it economically feasible.  This was intriguing, because I had just completed an analysis of the world trade in timber products with an economist.  We had calculated that all of the world trade in timber for fiber and construction could be met with plantations on good land that would require less than ten percent of all the forest land in the world.  Here was an example of what we had proposed: Use land subjected naturally to frequent disturbances, whose trees are resilient and productive, and respond well to frequent harvests.  A field of cottonwoods, natural in this location, would benefit wildlife and fish as well.  Here was a way that farming and conservation could come together.

The scenery at Arrow Rock was not a duplicate of what Clark saw, in part because of natural changes in the location of the river channel and backwaters, in large part because of the channelization of the river.  But it was an exact replication of the ecological processes he observed.  Cottonwoods grew in the same abundance and after disturbance to the bottomlands just as Lewis and Clark had described them almost 200 years before us, and the species of trees changed with their elevation above the river just as Clark had said.  These patterns and processes are gateways to  opportunities to restore the landscape.  Given a good habitat, a small number of mature cottonwoods can provide the seeds to fill a valley.