With their spectacular and often mysterious scenery, mountains always lure hikers, whatever the season. But their high ramparts also endure some of the roughest weather on Earth. In the lower 48 states, mountain hikes from the Pacific coastal ranges to the Appalachians tend to be rewarding in autumn -- thanks to fewer crowds, foliage displays, and crisper temperatures. Always stay abreast of current weather conditions and be prepared for early-season snowstorms, which can cripple road access and threaten the ill-equipped hiker.
Autumn is a beautiful time to explore the Appalachians because of the richness of these ancient mountains' deciduous forests. As might be expected, snow typically comes earlier to the high country of the northernmost ranges; the Southern Appalachians generally experience milder winters. The Poconos of Pennsylvania, one of the most southerly of the Northern Appalachian ranges, may be snow-free until November. Hiking to the summit of Camelback Mountain at Big Pocono State Park in autumn can reward with dazzling foliage displays across the broad, multistate vista.
The golden blaze of quaking aspens and the diminished threat of high-country thunderstorms are bonuses to autumn hiking in the Rocky Mountains. Of course, the chain's high elevations and continental exposures mean fierce snows may descend early in autumn. Once snows shudder the high country, you can still find good hiking opportunities at lower elevations, particularly on the east flanks of the range where precipitation is less. In Colorado's Rocky Mountain National Park in the Southern Rockies, for example, the Park Service recommends east-front trails under 8,700 feet in winter for hiking without skis or snowshoes; the snow encountered (outside of active storms) will typically be modest and well-packed on the route.
The Cascade Range
The Cascade Range is one of the snowiest places on the continent, owing to its presentation of high mountain ramparts to moisture-laden storm systems fresh off the nearby Pacific Ocean. The loftiest points, including the dramatic stratovolcanoes like Mount Rainier, are snowbound all year. Yet the lower elevations of the western drainages, where the maritime-influenced temperatures are balmier, may be snow-free throughout most of the winter. An October or November hike into the Western Cascades of Oregon or the cliffs of the Columbia River Gorge, which burrows through the Cascades along the Washington-Oregon border, reveals crimson and yellow vine maples in the shadowed understory of giant conifers -- and you may run into the first of the season's snowpack along knife-edge ridgelines.
The Sierra Nevada
California's High Sierras, roughly in-line to the south with the Cascades, receive an impressive winter dousing of snow, as well. Autumn snowstorms may descend early and complicate access to the alpine country. But elevations below about 4,000 feet tend to see a lot of rain in the winter. In places like Sequoia and Kings Canyon National Parks, you can often get up into the middle elevations -- between 4,000 and 7,000 feet -- with their famously rich conifer forests into November, recognizing still the possibility for early snows. Low-elevation trails in those parks, like the chaparral hike to Marble Falls, are good options if the upper slopes whiten early.