Editor’s Note: This article was written at the request of the Black Hills Knowledge Network, where information on the Arboretum, its plants, and rangeland scientist Ralph Cole will be archived with other local history.
On a spring day, the swath of trees north of the intersection of Mountain View Road and Jackson Boulevard is dappled by a pastel cloud of pink, yellow and white: crabapple, quince, forsythia, pear, cherry, plum and chokecherry trees and shrubs in bloom. This open area with its distinctive “1111 Mt. View Road” sign is the Ralph Cole Arboretum.
An arboretum may be planted to show exotic trees, such as the Dwarf Conifer Collection at the Minnesota Arboretum, or specialty collections like the Denver Botanic Gardens’ Oak Grove. But Ralph Cole’s mission was soil conservation, and his arboretum is all about trees for windbreaks, soil stabilization, and the wildlife benefits of native trees and shrubs.
Cole was a rangeland scientist with the U.S. Soil Conservation Service, and even in retirement devoted his energy to conservation. A volunteer, he designed and planted the arboretum in 1979 as part of the ongoing efforts to preserve the greenway along Rapid Creek after the 1972 Black Hills Flood. Cole selected trees from the Soil Conservation Plant Materials Center in Bismarck, North Dakota, from the South Dakota State University research nursery in Brookings, from Canada, Iowa, Nebraska and from Black Hills area nurseries. The guiding principles for the selections were that the trees would do well as windbreaks and yard plantings. They had to be heat, cold and drought resistant, and be able to withstand pests and disease.
Cole paid attention to the plants’ contribution to wildlife habitat and food for wild birds. If they bore edible fruit or provided colorful leaves in autumn, all the better. Trees that were new to West River and demonstrated for the first time in the Arboretum included certified varieties Cardan Green Ash, Sakakawea Buffaloberry, Oahe Hackberry, Meadowlark Forsythia, Midwest Crab, and Harbin Pear, and a number of trial varieties not yet certified for the area.
A candidate for the Eagle Scout recognition in 2002 compiled a list of the trees, their location in the Arboretum with GIS coordinates, and their condition. Not all the varieties remain, but one can still see many species as well as a maple grove, a cottonwood grove, and a bed of ornamental evergreens. You can download a copy of the list here.
The Arboretum was not Cole’s only contribution to the greenway and flood prevention. When consultants from Denver helped Rapid City plan its restoration of the flooded land along Rapid Creek, they included recommendations to seed 120 acres for playground and park use, and 60 acres as natural areas. Cole’s expertise in native plant species guided the selection of what grasses to use and where the tallgrass prairie sites would be created. One was near the Central States Fairgrounds, but was eventually overtaken by industrial development. Another — between West Boulevard and the former Black Hills Packing Plant — was developed into Executive Golf Course in 1989. The third and longest enduring was planted east of Jackson Park. It has since given way to a disc golf course, but in its day boasted big bluestem, little bluestem, sand bluestem, sideoats grama, switchgrass, prairie sandreed and Indian grass.
While these 20 acres of prairie natural area lasted, they provided a glimpse into what the dominant South Dakota landscape would have looked like more than 100 years ago, Cole told a Rapid City Journal reporter in 1986. “This was open savannah,” Cole told Dick Rebbeck while standing waist deep in autumn-hued prairie grasses. According to the article, “On the western shortgrass plains, however, true prairie occurred only in a few pockets, such as where larger streams emerged from the Black Hills.” The same natural features, soil and moisture that allowed the tall grasses to grow, made this area attractive to settlers and conducive to the “hay camp” that was the beginning of the settlement that would grow into Rapid City.