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California Wine Atlas

Spring Mountain District

Sub-AVA · Napa County · District 4

27 CFR 9.143 · established 1993-05-13

Heat class III · 1991-2020 normals

Climate normals in three numbers

3,469°F-days

, Apr 1 – Oct 31

7 GridMET cells cover this region

III

174mm

season rain, Apr 1 – Oct 31

56 mm of it in the , Sep 1 – Oct 31

Warm and cool vintages since 1980

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Rain across the season, and at harvest

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The boundary

This boundaryClick to open

Hovering a shaded region names it; a click opens its page.

Measured vineyard area

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Drought categories, year by year

Napa County — not Spring Mountain District

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What's in the ground

6.0

pH, 1:1 water

13.7cm

, whole profile

87cm

to

Well drained

, dominant condition

Distribution across 61 · mean ◆, median │, p10–p90 bar

6.0
8.8%
20.4%
available water
13.7cm
depth to restriction
87cm

Dominant

  • 27.1%
  • 25.3%
  • 11.8%
  • 9.2%
  • 5.6%

61 map units · soil described over 99.2% of the region’s area · 3.0% is water, rock outcrop or other non-soil · 97% of the described area has a restrictive layer within the profile.

Sand, silt and clay, against every other appellation

CLAYSANDSILT

Loam

37% sand · 42% silt · 20% clay

Sandier than 27% of California appellations and clayier than 35%. Each grey point is one appellation’s topsoil; appellations nest, so this is a distribution of places rather than of land.

Plus 15% rock fragments by volume, which the triangle does not describe — the three fractions are of the fine-earth material only.

Elevation, slope and aspect

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Producers

A curated roster, not a census — only source-verified entries appear, 2772 published across the atlas.

Bearing acreage by variety

Napa County · District 4

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Price per ton

Napa County · District 4

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The appellation in federal law

The boundary, in the government’s own words (282 words)

(c) Boundary. The Spring Mountain District viticultural area is located in Napa County, California, within the Napa Valley viticultural area. The boundary is as follows: (1) Beginning on the Calistoga quadrangle map at the Napa-Sonoma county line at the boundary line between sections 18 and 19 in T8N/R6W. (2) Then east along the boundary line between sections 18 and 19 for approximately 3/4 of a mile to its intersection with Ritchie Creek at the boundary line between sections 17 and 20. (3) Then northeast along Ritchie Creek approximately 2 miles, to the 400 foot contour line in the northeast corner in section 16 of T8N/R6W. (4) Then along the 400 foot contour line in a northeast then generally southeast direction, through the St. Helena and Rutherford quadrangle maps, approximately 9 miles, past the town of St. Helena to the point where it intersects Sulphur Creek in Sulphur Canyon, in the northwest corner of section 2 in T7N/R6W. (5) Then west along Sulfur Creek (onto the Kenwood quadrangle map) and south to the point where it first divides into two intermittent streams in section 3 in T7N/R6W. (6) Then south along the intermittent stream approximately 1.5 miles to the point where it intersects the 2,360 foot contour line in section 10 in T7N/R6W. (7) Then southwest in a straight line, approximately .10 mile, to the unnamed peak (elevation 2600 feet) at the boundary line between Napa and Sonoma Counties. (8) Then in a generally northwest direction along the Napa-Sonoma county line, through sections 10, 9, 4, 5, 32, 33, 32, 29, 20, and 19, to the beginning point on the Calistoga quadrangle map at the boundary between sections 18 and 19 in T8N/R6W.