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California Wine Atlas

Chalk Hill

Sub-AVA · Sonoma County · District 3

27 CFR 9.52 · established 1983-10-21 · last amended 1988-05-13

Heat class III · 1991-2020 normals

Climate normals in three numbers

3,107°F-days

, Apr 1 – Oct 31

12 GridMET cells cover this region

III

158mm

season rain, Apr 1 – Oct 31

52 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

Sonoma County — not Chalk Hill

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What's in the ground

5.9

pH, 1:1 water

12.9cm

, whole profile

115cm

to

Well drained

, dominant condition

Distribution across 68 · mean ◆, median │, p10–p90 bar

5.9
1.8%
24.8%
available water
12.9cm
depth to restriction
115cm

Dominant

  • 26.1%
  • 14.6%
  • 12.3%
  • 11.8%
  • 8.5%

68 map units · soil described over 97.6% of the region’s area · 2.1% is water, rock outcrop or other non-soil · 65% of the described area has a restrictive layer within the profile.

Sand, silt and clay, against every other appellation

CLAYSANDSILT

Loam

38% sand · 38% silt · 25% clay

Sandier than 29% of California appellations and clayier than 71%. Each grey point is one appellation’s topsoil; appellations nest, so this is a distribution of places rather than of land.

Plus 20% 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

Sonoma County · District 3

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Price per ton

Sonoma County · District 3

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The appellation in federal law

The boundary, in the government’s own words (1,020 words)

(c) Boundary. The Chalk Hill viticultural area is located near the town of Windsor in Sonoma County, California. From the beginning point on the south line of Section 2, Township 8 North (T. 8 N.), Range 9 West (R. 9 W.) at the intersection of Arata Lane and Redwood Highway (a.k.a. Old Highway 101), on the “Healdsburg Quadrangle” map, the boundary proceeds— (1) Southeasterly along Redwood Highway through Section 11, T. 8 N., R. 9 W., to the point of intersection with Windsor River Road; (2) Then westerly along Windsor River Road on the south boundary of Section 11, T. 8 N., R. 9 W., to the point of intersection with Starr Road; (3) The southerly along Starr Road to the point of intersection with the south line of Section 14, T. 8 N., R. 9 W.; (4) Then easterly along the south line of Sections 14 and 13, T. 8 N., R. 9 W. and Section 18, T. 8 N., R. 8 W., to the point of intersection with the Redwood Highway; (5) Then southeasterly along the Redwood Highway to the intersection with an unnamed road that intersects the Redwood Highway at a right angle from the northeast near the southwest corner of Section 28 near Mark West Creek, T. 8 N., R. 8 W.; (6) Then northeast approximately 500 feet along the unnamed road to its intersection with the Pacific Gas and Electric power transmission line; (7) Then northeast approximately 1,000 feet along the power transmission line (paralleling the unnamed road) to the point where the power transmission line turns in a northerly direction; (8) Then in a northerly direction along the power transmission line to the point of its intersection with the south line of Section 17, T. 8 N., R. 8 W.; (9) Then east along the south line of Sections 17, 16 and 15, T. 8 N., R. 8 W. to the point of intersection with Mark West Road on the “Mark West Quadrangle Map”; (10) Then northerly for approximately 1.3 miles along Mark West Road (which becomes Porter Creek Road), then northeasterly for approximately 1.7 miles on Porter Creek Road to its intersection with the unnamed medium duty road that parallels Porter Creek in Section 12, T. 8 N., R. 8 W.; then northeasterly on the Franz Valley Road over the Tarwater Grade and continuing along the Franz Valley Road for approximately 3 miles to its intersection with Franz Creek (approximately 2,000 feet west of the range line common to R. 7 W. and R. 8 W. in T. 9 N. and approximately 1,150 feet north of the north line of Section 25, T. 9 N., R. 8 W.); (11) Then westerly along Franz Creek to its point of intersection with the east line of Section 21, T. 9 N., R. 8 W.; (12) Then southerly along the east line of Section 21 to the southeast corner thereof; (13) Then southerly, approximately 0.08 mile, along the west line of section 27, T. 9 N., R. 8 W., to the point at which an unnamed unimproved road which parallels the south bank of Martin Creek intersects the west line of section 27, T. 9 N., R. 8 W.; (14) Then southeasterly, approximately 1.07 miles, along said road to the point at which the road is crossed by the east line of section 27, T. 9 N., R. 8 W.; (15) Then southerly, approximately 0.65 mile, along the east lines of sections 27 and 34, T. 9 N., R. 8 W., to the point in the northeast corner of section 34, T. 9 N., R. 8 W. where the north fork of Barnes Creek intersects such line in section 34, T. 9 N., R. 8 W.; (16) Then continuing along the north fork of Barnes Creek, approximately 0.5 mile, in a generally westerly direction to a small dwelling at the eastern terminus of an unnamed unimproved road (known locally as the access to the Shurtleff Ranch) in section 34, T. 9 N., R. 8 W.; (17) Then continuing in a generally westerly direction, approximately 1.4 miles, along the unnamed unimproved road (known locally as the access to the Shurtleff Ranch) to its intersection with an unnamed unimproved road (known locally as Spurgeon Road) in section 33, T. 9 N., R. 8 W. on the Healdsburg, California, Quadrangle Map; (18) Then westerly, approximately 0.45 mile, along the unnamed unimproved road (known locally as Spurgeon Road) to the point where the road intersects Chalk Hill Road in section 32, T. 9 N., R. 8 W.; (19) Then in a generally northwesterly direction, approximately 1.3 miles, along Chalk Hill Road to the point where Chalk Hill Road crosses Brooks Creek in section 29, T. 9 N., R. 8 W.; (20) Then north in a straight line, approximately 0.2 mile, to the top of a peak identified as Chalk Hill; (21) Then west-northwesterly in a straight line to the confluence of Brooks Creek and the Russian River; (22) Then westerly along the Russian River to the point of intersection with the range line common to R. 8 W. and R. 9 W. in T. 9 N.; (23) Then southwesterly in a straight line to the point of a hill identified as having an elevation of 737 feet; (24) Then south-southwesterly in a straight line to the point at the easterly terminus of Reiman Road; (25) Then southwesterly in a straight line to the point at the intersection of the township line common to T. 8 N. and T. 9 N. in R. 9 W. and the frontage road (a.k.a. Los Amigos Road) for U.S. Highway 101; (26) Then west approximately 3,000 feet along the township line common to T. 8 N. and T. 9 N. in R. 9 W.; (27) Then southerly for approximately 2,000 feet in a straight line to the point of intersection with an unnamed stream drainage; (28) Then east in a straight line to the point of intersection with Eastside Road; (29) Then northeasterly along Eastside Road to the point of intersection with Redwood Highway; (30) Then southeasterly along Redwood Highway to the point of beginning.