This week the first heavy rains came to the Bay Area. This causes a stir of anticipation in me as I think about our local mountain. When the rains bring back the grasses, Mount Diablo begins to don a rich green shawl. The dormancy of summer ends this time of year and the transformation happens almost imperceptibly, a slow emerald spread across the flanks of the mountain. At its peak, in the clear, cool light of winter sunshine, the flare of green simmering on the mountain is magnificent. When I first saw Mount Diablo in 1988, this fine green shawl was thrown over her shoulders. My landing area in California was in the East Bay hills near Mt. Diablo in Orinda Village. I lived in a former monastery. Outside the window of my room loomed a hillside made verdant by recent rains. It was evocative of the rolling hills of my native Midwest in spring. Except that, here in California, the rains come in winter. Across San Francisco Bay is Mt. Diablo’s sister mountain, Mount Tampalpais. The two mountains are a study in contrasts. Mt. Diablo is drier, lighter, more open, and hot in summer. The habitat is primarily oak scrubland interspersed with coyote bush and the remnants of grazing land. Mt. Tam is dark, moist, cool, often fogbound, and shrouded with pine and redwoods. They could not be more different in temperament and personality. I’ve been getting to know the temperament of both mountains over the past twenty-odd years after hours spent on their trails. But the changing moods of Mt. Diablo hold a special place in my heart. My sensitivity to those moods became more pronounced for me during the several years I commuted on the BART train between Oakland and Walnut Creek. When I stepped onto the platform at the beginning and end of each day, I was greeted by a clear view of the mountain. What I began to notice was that each day brought a unique hue, a changed aspect to the mountain. I began to realize that as stationary and permanent as mountains seem in contrast to our rushed and harried lives, they are anything but static and unchanging. They shape-shift in an un-ending dance of light, rock, plants, clouds, rain, and wind. The color green reflects just one of Mt. Diablo’s many moods. The range seems to span the spectrum of a painter’s palette, from melancholy indigo to jubilant gold; from angry thunderhead grey to glowing amber; from sullen fog-bound to the washed ochre of summer; and everything in between. The green on Mt. Diablo is also the most ephemeral and brief of colors; its mood doesn’t last. But it wasn’t always so. Before cattle ranching overran the mountain, the green endured for much of the year. The native peoples, the Miwok and Ohlone, who believed the mountain to be the origin of creation, would have experienced a very different mountain, one that stayed green throughout much of the year. This is because the native grasses that populated Diablo’s flanks in pre-European times were well-adapted to the semi-arid climate. They had roots that grew far into the soil and so they retained their verdancy into the hot, dry summer. The grasses introduced by cattle ranchers grew fast and abundantly but had shallow root systems. Largely dominant on the mountain today, these invasive plants quickly dry up and go dormant in the summer heat. Now, I’m perched high up on Sugarloaf, one of two ridges cradling my home on San Crainte Creek. I look at the ground at my feet and see that the rain is already summoning forth the first tender blades from their summer sleep. To the east, Mt. Diablo seems to simmer in anticipation, reflecting my own mood. Faint necklaces of emerald are beginning to glimmer on her flank. The season, however short, is imminent, and I’ll be here to witness its passage. Summer dormancy is an odd thing for a native midwesterner like myself. Winter is the dormant season in the Midwest, not summer. The dead grasses of summer in California lie down on the hills like the cover of snow in an Iowa winter. Plants go dormant here in order to endure the searing heat and dry air, instead of waiting out the bone-biting cold of a Midwest winter. In winter here, the rains coax the grasses from their slumber. In the Midwest, the rains do their conjuring in spring. To get some semblance of a Midwest winter, you have to go to the higher altitudes in California. The body knows what it knows and adjusts accordingly. Eventually. But not without some longing for what its known.