(CN) -- Dave Willis rides a mid-size gelding named Chance through towering firs interspersed with ponderosa and lodgepole pine as spruce and hemlock hover over a forest floor covered with Jurassic fern. As the executive director of the Soda Mountain Wilderness Council navigates through the southern reaches of the Cascade Range, lichen hang from the branches of the coniferous trees, swaying in the wind. At mid-June, the wildflower bloom is nearing its peak.
The weather forecasters called for afternoon thunderstorms, but the rain has stayed away all day, and the forest is awash in quiet except for wood snapping under the horse’s hooves.
“This is a classic old-growth remnant forest,” Willis says. “You don’t see much of these around anymore.”
This forest is intact, retaining the character it's maintained for centuries, because of the conservation endeavors of Willis, his organization and the many allies that contributed to the effort to create and expand the Cascade-Siskiyou National Monument.
The monument straddles the California/Oregon border, encompassing roughly 87,000 acres of forest, grassland and mountain peaks in the region where the Cascade Range collides with the geologically distinct Siskiyou Mountains.
“This is the only monument established for the sole purpose of preserving biodiversity,” said Shannon Browne, the community-partnerships director for the Friends of the Cascade-Siskiyou National Monument and a proponent of preserving the monument’s current borders.
The monument was established because the area represents an intersection of several different biological zones. On its eastern fringe, a portion of the Klamath Basin hosts the same array of vegetation – including sagebrush and juniper – found elsewhere in the Great Basin that covers territory spanning Utah, Nevada, Idaho, California and Oregon.
To the south, the Siskiyou Mountains, an approximately 100-mile coastal mountain range that begins at Crescent City, California, has its terminus at the monument. The range brings its own mix of flora and fauna, including coastal Douglas fir, California white fir, Lawson’s cypress and the distinctive weeping spruce, as well as the endangered Siskiyou Mountains salamander.
The monument not only features the aforementioned forests of the Cascade Range but also encompasses the oak woodland typical of the western slope of the Sierra Nevada. These biological zones do not remain distinct and apart within the monument, but instead intermingle in what Willis describes wryly as an “ecological mulligan stew.”
“It’s the most botanically diverse coniferous forest in North America, if not the world,” Willis said.
Browne agrees, calling the area of “global botanical significance.”
Willis said the monument not only preserves biodiversity but provides regional connectivity.
“Klamath Siskiyou is the most botanically diverse coniferous forest in North America, if not the world,” Willis said. “And if Klamath Siskiyou is the Noah’s Ark, Cascade-Siskiyou is the loading dock to the ark.”
Ecologists who worked with federal land management agencies such as the Bureau of Land Management first recognized the significance of the area in the early 1980s.
That was when Willis became involved in advocacy for the preservation of the area that is now the monument, although the first push was to get a “wilderness area” designation, which carries much stricter development prohibitions than monument status does.
Willis got his wish in 2009, when former President Barack Obama designated a 24,000-acre swath inside the monument as the Soda Mountain Wilderness, making any type of development on those lands forbidden.