Abstract An analysis of a 3-yr database (1986–88) acquired new Mount Mitchell (35°44′05″N, 82°17′15″W, 2038 m MSL) where the forest consists primarily of Fraser fir and some red spruce stands is presented. The site was immersed in clouds for 28%–41% of the time during each of the three growing seasons (15 May–15 September). This study only investigated extreme episodes of wet (cloud-water pH% ≤.3:1)and dry (eg., an ozone concentration ≥ 70 ppb) acidic deposition. Extreme wet events occasionally relieved periods of high ozone (≥ 70 ppb) exposures during the final field intensive. Extreme wet and dry events could activate the decline mechanism in any above cloud-base forest, especially if the trees are exposed to such events during very early or very late stages of their Lives. The exposure of the forest to natural climatic stress, such as drought condition wintertime temperatures during the growing season, snow storm during early spring, etc., would also subject the forest to a stressful period during whic...