Montgomery Woods State Natural Reserve, Protected forest reserve in Mendocino County, United States

Montgomery Woods State Natural Reserve protects 1,323 acres at the headwaters of Montgomery Creek, a tributary of Big River, in a steep valley of Mendocino County. Its old-growth coast redwoods grow in an upland riparian meadow habitat, unlike most preserved groves on alluvial plains. A trail climbs about three-quarters of a mile from the Orr Springs Road parking area, then loops three miles through the grove, much of it on boardwalks.

The area began as a donation in 1945 when Robert Orr gave land to establish the reserve, which was later expanded through acquisitions by a conservation organization. This gradual growth helped protect an increasingly larger section of old-growth forest.

The reserve's name comes from Montgomery Creek, whose headwaters it protects. Since 1947 the Save the Redwoods League has donated 765 acres, and the grove is now a stop on the Redwood Coast route between Ukiah and Comptche. Visitors can look for the Mendocino Tree, deliberately left unmarked so that foot traffic does not compact the roots.

Access is from a parking area on Orr Springs Road, 13 miles west of Ukiah and 15 miles east of Comptche. A moderately steep trail climbs about three-quarters of a mile along Montgomery Creek to the grove, where a meandering three-mile loop uses boardwalks over the forest floor. Trails often flood in colder months during heavy rain.

The Mendocino Tree, one of the tallest coast redwoods in this grove, was the world's tallest known tree from 1999 to 2004, until taller trees were found in Humboldt County parks. It was deliberately left unmarked to protect its roots from trampled soil, since earlier publicized champion trees were damaged by crowds walking around their bases.