When Central Oregonians think of Douglas firs, we usually envision the majestic coastal firs. But Central Oregon has a distinct inland variety, the Rocky Mountain Douglas fir, which is morphologically and genetically different from its coastal cousin. Occurring from British Columbia south to New Mexico, these cold-hardy trees can grow up to 150’ in height, 6’-8’ in width and can live more than 500 years. A 30-acre grove of these old-growth firs is found on a short, easily-accessible hike at Candle Creek in the Mt. Jefferson Wilderness.

Tucked away in a seldom-visited corner of Fremont-Winema National Forest, just a half-hour drive east of Highway 97 south of Crescent, is a collection of groundwater-fed fens (peat wetlands) supporting some of the richest concentrations of rare and distinctive plants in the Pacific Northwest. Formed in thick deposits of volcanic pumice from the eruption of Mt. Mazama 7,700 years ago, these fens are permanently wet year-round, with a fascinating assortment of mosses, sedges, wildflowers and even carnivorous plants.

Hidden and nearly unnoticed in the canyon lands above the Metolius River arm of Lake Billy Chinook are several small bowls with unique geologic formations, known as the “balanced rocks.” Carved by erosion over eons of time, these great slabs of rock weighing many tons are poised up to thirty feet in the air above pinnacles of softer rock. First recorded in 1855 by a railroad survey party traveling in the area, these balanced rock formations are accessible today by a short hike from a good road about thirty driving miles west of Culver.

The original railroad surveys of the Deschutes River Canyon, conducted in 1855 by Army engineers, concluded that “the Deschutes Valley is mostly a barren region…separated from the rest of the world by almost impassable barriers.” In fact, at the turn of the century, Central Oregon was the largest territory in the U.S. without a railroad. Only in the early 1900s, when its wealth of ponderosa pine was recognized by commercial interests, was serious rail construction begun south from the Columbia up the Deschutes River. Hikers today can follow a section of this now abandoned rail bed for many miles, with spectacular river and canyon views.

In our scientific age, it’s hard to believe that the origins of any landform could still be unexplained, but this is the case with the extensive soil mounds and their encircling rock rings found northeast of Madras on the Shaniko Plateau. Known as mima (my-muh) mounds, several theories have been advanced about their formation, from differential erosion, to Ice Age freeze-thaw cycles, to soil movement by foraging gophers. But no one theory is widely accepted and these unusual land features remain a puzzle to geologists today. Hundreds of acres of this mima mound topography can be explored on BLM land near Shaniko.

One magnificent spectacle of nature that recurs every fall in Central Oregon is the spawning of kokanee salmon in the tributary streams of local Cascade lakes. Though an introduced species, these landlocked, lake-dwelling sockeye salmon are no less impressive. Several local streams have kokanee runs in the fall, but three tributaries of Crane Prairie Reservoir — the Upper Deschutes, Cultus and Quinn Rivers — are less-visited, beautiful and easy to access. If looking for an outing on a warm, sunny day in late September or early October, these three kokanee spawning sites are worth a visit.

What the heck are fens? Unlike bogs, which are acidic, low in nutrients and dominated by sphagnum moss, fens are fed by mineral-rich groundwater, creating neutral or alkaline peatlands with a rich diversity of brown mosses, sedges, wildflowers and even carnivorous plants. Along the east slopes of the Cascades in Central Oregon, fens are rare, occurring only between 4,500’-6,000’ in isolated perched aquifers over slow-draining glacial till from the last Ice Age. Two secluded but accessible fens can be found near Little Cultus Lake.

Spring-derived streams are fairly common along the eastern slopes of the Cascade Range in Central Oregon, including the Metolius River, Cultus River, Quinn River, Brown’s Creek and Fall River. The combination of heavy precipitation along the Cascade crest, permeable volcanic bedrock, plus groundwater flow serves to recharge all of these spring-fed streams. But Fall River has been the most extensively studied as a local indicator of climate change — besides having a delightful hiking trail along its banks to explore.

Sometimes the distinctive natural landforms of a place combine with centuries of human activity to create an exceptional mix of geography and history. The Klamath Marsh Narrows is such a place. This three-quarter mile crossing, in the midst of 65 square miles of sprawling marshland, has been used by Native Americans for millennia, by the John C. Fremont expedition in 1843, and by travelers down to the present day. It’s one of the best birding spots in Central Oregon, and hikers can follow in Fremont’s footsteps along the edge of the grasslands, enjoying solitude and sweeping Cascade mountain views.

What are tumuli (besides the plural of tumulus)? From the Latin tumidus, meaning swollen or bulging in shape, a tumulus is a circular, domed lava structure up to 30’ high and 60’ in diameter, formed by the upward pressure of actively-flowing lava against its cooling crust. Along with its elongated cousin, the pressure ridge, these fascinating lava formations can be explored on a less-traveled trail in the Badlands Wilderness, just 15 miles east of Bend.