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.

Hydrology of the Pumice Fens

Snow falling on the Walker Rim and in the headwaters of Jack Creek feeds a system of shallow aquifers within the 5’-10’ of volcanic ash and pumice deposited over the area by Mt. Mazama’s eruption. In places where the pumice deposits have been eroded, mainly along pre-eruption stream courses and bedrock fault lines, this groundwater flow reaches the surface (diagram at left). Over thousands of years, due to the slow decomposition of plants in these waterlogged soils, deposits of peat have built up.

Core samples taken from the Wilshire Meadow and Dry Meadow fens show that these peat deposits are up to 60” deep. Studies of similar fens in the Northwest indicate that peat accumulates at a rate of about one inch per century — making these fen wetlands at least 6,000 years old.

Indicator Plants of the Pumice Fens

Unlike a regular forest meadow, which is soaked by snowmelt in the early spring and then dries out as the summer progresses, fens receive a perpetual flow of groundwater to their surface, saturating the peat soils throughout the year. As a result, fens contain special plant communities that have evolved and adapted to this permanently soggy environment.

Most noticeable when first encountering a fen are the abundant brown mosses covering the spongy soil surface. Intermixed with these mosses are unique species of sedges and rushes. Also gracing the pumice fens in spring are signature species of wildflowers, including shooting stars, saxifrage, monkeyflowers, bog orchids and elephant’s head. Around the drier edges of the fens, one finds thick masses of bog blueberry shrubs.

Photo Source: Paul Slichter

Perhaps the most unique plants found in these fens are the insect-eating sundews and bladderworts. The leaves on these plants have hairs with drops of sticky dew, which entrap any insect that ventures too close. As the insect struggles to escape, the leaf folds over it, enclosing it so the plant can digest it and extract its nutrients. Danger in the fen (if you’re an insect)!

Visiting the Pumice Fens

Though there are nearly 40 fen wetlands in the Jack Creek Headwaters, three of these stand out for their large size and their ease of access — Crooked Meadow Fen, Wilshire Meadow Fen and Dry Meadow Fen (see the Road and Hiking Map downloads below).

These three fens are all within a mile of one another and each is less than a half-mile off gravel Forest Road 94, a half-hour drive east from Hwy 97 south of Crescent. They can easily be visited in a one day trip from Bend, with an hour-and-a-half drive to and from. Overnight camping is also an option, with the parking area at Crooked Meadow Fen likely the best choice, as it has space for anything from tents to travel trailers. Be sure to bring plenty of mosquito repellent if visiting during the late spring/early summer months.

At over 5 acres, Crooked Meadow Fen is one of the larger and more interesting fens to explore, as it winds for over a half-mile through the pine forest. Since it’s unfenced, cattle may be encountered here during the July-September grazing season. The Wilshire Meadow Fen is an intimate, fenced wetland just one acre in size, but since it branches into several forks, one has good close-up views of the plants from its dry banks. At nearly 7 acres, the Dry Meadow Fen is an elongated, fenced wetland extending more than a half-mile north to south. An abundance of wildflowers can be seen here in early summer, especially in the northern half of the fen (see Hiking Map download below).

Always, please remain aware that these fens contain some of the most rare and sensitive plant species in the entire Forest, so avoid walking on the fragile, wet moss beds!

Download (PDF, 884 KB): Photos of the Pumice Fens
Download (PDF, 473 KB): Road Map to the Pumice Fens
Download (PDF, 782 KB): Hiking Map for the Pumice Fens

DISCLAIMER: Every effort has been made to ensure the accuracy of this information, but the authors do not guarantee that it is either current or correct. The reader assumes full responsibility for any use of this information, and is encouraged to exercise all due caution while recreating.