Napa, read in elevation.

The valley in section

The floor falls steadily from Calistoga at roughly 350 feet to the town of Napa near sea level. The Mayacamas run alongside it the whole way, holding somewhere near 2,500. Every property in the county sits inside that band. The active engagements are plotted below at surveyed elevation.

Hover a point to read it.

The line at 1,400 feet

The appellation boundary is a weather line.

The marine layer settles into the valley overnight and burns off through the morning. It has a ceiling, and that ceiling sits near fourteen hundred feet. Below it the day starts cool and grey. Above it the day starts in sun.

When the Howell Mountain appellation was drawn in 1983, the first sub-appellation in Napa Valley, its boundary was set along the 1,400 foot contour rather than along a road or a parcel edge. The line on the map is the fog line.

For vines this reorganises the whole season. Above the fog the light arrives earlier and runs more direct, while the nights fall colder than the floor. Fruit ripens slowly and the skins come in thicker. For a buyer the consequence is simpler. An acre on the mountain and an acre on the floor are different assets, priced differently, whether or not anything is planted on either one.

What height costs

Elevation is bought with time and with capital.

The view from a ridge is the easy part of the decision. Three practical items account for most of the difference between a hillside property and a valley floor one, and they are worth understanding before a second visit rather than after.

The drive

Roads into the hills were cut to follow the grade, so straight-line distance tells a buyer almost nothing. A parcel two miles from a main street can be a fifteen minute drive. This is the item buyers most often underestimate, and the only reliable way to judge it is to make the drive at the hour you would normally make it.

Services

Addresses inside St. Helena and Calistoga generally connect to municipal water and sewer. Above the towns, most parcels run on a well and a septic system. Both are ordinary in the hills and neither is a problem, but each is a capital item with its own inspection and replacement schedule, and each belongs in the diligence.

Building

Slope adds cost before anything is framed. Access, grading, drainage, and engineered foundations all scale with the pitch of the site. Hillside work in Napa County also carries a longer review than equivalent work on the floor, which is a schedule question as much as a budget one.

Three bands

The same county behaves differently at three heights.

The marine layer divides Napa more sharply than any road does. Below it, above it, and the uncertain ground in between behave as three separate places, with different seasons, different services, and different reasons to buy. Settling which band a property belongs to answers most of the other questions in advance.

to 500 ftThe floor

Everything from the city of Napa up through Calistoga, including the towns and the open land between them. Under the fog every morning, which is why the floor runs warmer by day and ripens earlier. Two unlike propositions share this band: town addresses on municipal water and sewer, walkable and lot-sized, and open parcels on wells that run to twenty acres and past it. Most of the valley's planted vineyard sits here.

500 – 1,400 ftThe slope

The climb on either side of the valley. The least predictable band in the county, above the marine layer on some mornings and inside it on others. Views begin here, and so does the longer drive, the well and the septic system, and the point at which a build starts answering to the pitch of the ground.

1,400 + ftAbove the fog

Howell Mountain in full, and the upper reaches of Spring Mountain, Mount Veeder, and Diamond Mountain. A growing season unlike anything below it: light arriving earlier and running more direct, nights falling colder, fruit taking its time. These are the longest drives in the county, and the band where the reason for buying is almost always the land rather than the house.