The historian Wallace V. Ohles recounts the area's origins: By 1884, there were three families in the Geneseo District: those of Charles Pepmiller, the Herts and the Gruenhagens.

Barbara Mathis, for example, emigrated to the United States from the Alsace region in Europe in 1868 and eventually settled in Geneseo, Illinois.

[7] There, she married William Ernst, and the two of them moved to the new settlement of Geneseo in San Luis Obispo County in 1884.

[8] The call for settlers that had been placed in the Geneseo, Illinois newspaper also stated "we need a few families to help start a Lutheran Church – good farm land.

[9]Geneseo District, like the other small rural enclaves in San Luis Obispo County, suffered from declining population as the City of Paso Robles and other larger towns in the region grew.

Today, the Geneseo District is thriving once again due to the growth of the Paso Robles wine industry and the influx of new vineyards and wineries.

The hillside and hilltop vineyards of the Geneseo District viticultural area expose the grapevines to the cooling influence of the winds and sea breezes that enter the region through gaps in the crest of the Santa Lucia Range.

The hillside and hilltop vineyards also are protected from frost, because cold air drains off of the high slopes of the viticultural area at night and into the lower elevation valleys.

In the summer and fall, cool marine air travels inland and eastward over the crest of the Santa Lucia Range through the Templeton Gap and into the Geneseo District viticultural area.

Occasional incursions of marine air can also travel southward along the Salinas River from Monterey Bay and reach the hills of the Geneseo District.

(Daily temperature records and GDD data were gathered from 2002 through 2006 at the 980-foot elevation weather station of the Jerry Reaugh Branch Vineyard.)

Area soils tend to be cemented by carbonates and silicates, which provides reduced rooting depths and moderate water holding capacity, drainage, and vigor.

The soil series form a topographical sequence of types by slope position, from ridge-crest to shoulder-slope, mid-slope, foot-slope, and toe-slope.

The Huerhuero residual soils are primarily Mollisols with darker and more organically rich horizons, leached at the surface.

Large plantings were first made in the 1970s, but major growth in Geneseo District viticulture, like much of the Paso Robles wine region, did not come until the early 1980s.

In 1982, Arciero Vineyards/EOS Estate Winery, now with over 700 acres (280 ha) and production at 160,000 cases, pioneered the planting of several premium Italian varietals in the Paso Robles region.

Robert Hall, with Howie Steinbeck's advice, bought the land for his Red Tail Vineyard in 1995.

Today, Geneseo District is home to approximately 3,000 acres (1,200 ha) throughout 21 vineyards and at least 16 bonded wineries.