Written by Abby Nichols of the Northwest Nature Shop, Nature Conservancy Volunteer Field Assistant
The Table Rocks are distinct landmarks of the Rogue Valley – two horseshoe-shaped geologic features sitting squarely between the Cascade and Siskiyou Ranges in Southern Oregon. Remnants of a prehistoric lava flow, these archaic rock formations are home to a variety of wildlife species and habitat types, as well as wildflowers, hiking trails, vernal pools. and a number of protected and endangered plant and animal species.
The Table Rocks ecosystem “matrix” is a landscape shaped by historic fire. An important region for the Takelma tribe, the plants, animals, and terrain of the Table Rocks supported the traditional people who formerly occupied the area. Now, the site is managed cooperatively by The Nature Conservancy and the Bureau of Land Management, and projects and management decisions are coordinated with the Confederated Tribes of the Grande Ronde and the Cow Creek Band of the Umpqua Tribe of Indians, who signed a Memorandum of Understanding in 2011 and 2012.
A site of fascination for budding botanists, ecologists and seasoned land management professionals alike, the Table Rocks offers a unique respite from the development that occupies the Rogue Valley floor.
Vegetation varies from place to place on the sides and raised surface of the two mesas. The terraced slopes of the Table Rocks feature deep soils with fair drainage on the terrace steps, while shallow, drier soils and conditions are found between the steps. Broken rock and foreign-looking coagulates of stone are scattered across the slopes, smothering soils. This interplay of topography and soil makes the Table Rocks a site of diverse plant morphology.
The Oregon white oak (Quercus garryana), the area’s best-known resident, is a good example of this effect. On the steep pitches, white oaks are small and scrubby with flat, stunted tops, and have limited access to soil resources. They grow tightly together with narrow stems, and are close in size to surrounding shrubs.
But on the ledges, where soils are deeper and feature a cooler micro-climate, this same species thrives. Here, oaks grow large and thick and have complex branch forms. Leaf-shade keeps the ground cool and limits competition from other plants. Groves of multi-stemmed madrone trees (Arbutus menziesii, an evergreen species with reddish bark that unpeels to reveal a slick, green underside), are found in broad patches, or are interspersed with oaks throughout the landscape, shading the ground with broad, leathery leaves. Here and there, incense cedars grow ambitiously in the shadows, and Fremont’s silktassel (Garrya fremontii) droops with blue and purple fruits. Fine tendrils of native honeysuckle weave throughout, climbing oaks and birchleaf mountain mahogany (Cercocarpus betuloides). Wildflowers – like Henderson’s fawn lily (Erythronium hendersonii) and shooting stars (Dodecatheon meadia) – bloom in the cool, quiet spaces with delicate rosettes of leaves.
On the drier slopes, mountain mahogany and California black oak grow alongside the more-common Oregon white oak, and open up to large patches of chaparral habitat. Chaparral is a term used to describe a kind of mixed vegetation habitat characterized by dry shrubs and scrub, such as manzanita and spiny buckbrush. In the spring, the chaparral of the slopes and surrounding areas of the Table Rocks blooms with white flowers, and attracts pollinators like native bees and butterflies.
But beware: poison oak also prefers these dry, sun-baked slopes and the shallow soils of Table Rocks, so watch out as you travel, and wash up if you brush up against any stems or leaves.
On the upper slopes of the Table Rocks, tall Douglas fir trees and ponderosa pine mingle with white oak stands, pushing up through the canopies of the oaks. Raptors, such as peregrine falcons, occupy the ledges near these tall individuals, and use the height of the conifer limbs to scan for prey. Below, deer tracks form tight trails along the slopes, cutting down into gullies and through drainages, and large swaths of buckbrush. Deer forage on buckbrush, nibbling on fresh, young greenery, and browse other, tender plants.
Another special feature of the Table Rocks are its ephemeral, seasonal “vernal pools.” Called vernal pools due to their appearance in low areas in mounded terrain during winter months, these temporary pools support a variety of life, including an endangered “shrimp” species and a palette of perennial, native plants. In recent years, however, non-native and noxious weeds have placed pressure on native species, competing for resources and – some speculate – changing the water chemistry of the local pools. Thankfully, land managers and volunteers alike have actively participated in stewardship efforts at the Table Rocks Preserve.
Spring is the season for wildflowers on the Table Rocks, and two trailheads afford access to the tops of the bluffs. At the summits of Lower and Upper Table Rock, visitors can observe “fields” of wildflowers and their pollinator companions. For more information, visit our store for tips and hiking advice, as well as to pick up one of our books about the Table Rocks area: Table Rocks of Jackson County: Islands in the Sky and Flowers of the Table Rocks