Kalmiopsis Wilderness, Wilderness area in the Klamath Mountains, southwestern Oregon, United States

Kalmiopsis Wilderness is a 179,755-acre protected area in the Klamath Mountains of southwestern Oregon, within Rogue River–Siskiyou National Forest. It is named for Kalmiopsis leachiana, a slow-growing rhododendron relative discovered there in 1930. The terrain ranges from 500 feet to 5,098 feet at Pearsoll Peak, with deep canyons, sharp rock ridges, and clear streams, including headwaters of the Chetco and North Fork Smith Rivers and part of the Illinois River canyon.

Gold discoveries in the 1850s brought miners to this region and led to mining settlements. Protection as a wilderness area came in 1964, ending extractive activities and preserving the landscape.

The name honours Kalmiopsis leachiana, a slow-growing rhododendron relative that Lilla Leach found in the Gold Basin area in 1930. Botanists consider it a relict of the pre-ice age and the oldest member of the heath family, Ericaceae.

The reserve holds about 153 miles of trail across 24 established routes, from the Chetco and North Fork Smith headwaters to part of the Illinois River canyon. Trails burned in the 2002 Biscuit Fire were still reopening as late as 2015, so check current conditions before setting out.

The eastern half lies on the Josephine ultramafic sheet, rock with very high iron and magnesium content. Historic chromite mines once worked this ground, and cabin sites, mines and ditches remain. The western half instead rests on Dothan formation sedimentary rocks and the igneous rocks of the Big Craggies.