What city is 98611 in?

98611 is a Castle Rock, WA mailing address. By land area, 2% lies inside Castle Rock; the rest is outside any Census-defined city or community.

What is the population of 98611?

About 9,302 people (±986), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 10,165.

What is the median household income in 98611?

$86,322 (±$12,746), compared with $98,141 for Washington as a whole. Half the households in the ZIP code earn more and half earn less.

How many carrier routes and mailboxes are in 98611?

8 USPS carrier routes with 3,918 residential and 51 business mailboxes (3,969 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.

What ZIP codes are near 98611?

The closest, measured center to center: 98645 (7 mi), 98593 (8.5 mi, Vader), 98581 (8.8 mi, Ryderwood), 98632 (10.4 mi, Longview), 98626 (11 mi, Kelso) and 98591 (12 mi, Toledo).

98611 ZIP Code, Castle Rock, WA

98611 is a ZIP code in Castle Rock, Washington in Cowlitz County. It covers 136 square miles of land. The closest ZIP codes are 98645, 98593 and 98581. 9,302 people live here in 3,539 households. It is rural, with fewer than 100 people per square mile, and most homes are owner-occupied (84%). Median household income is $86,322, below the Washington median of $98,141.

Quick facts

Mailing city: Castle Rock, WA
County: Cowlitz County
Land area: 136 sq mi
Population: 9,302
Median household income: $86,322
Carrier routes: 8 (3,918 homes)

Key figures

Measure	Value
Residents	9,302
Households	3,539
Median household income	$86,322
Income per person	$37,729
Median age	43.7
Homeowners	83.8%
Median home value	$425,700
Median rent	$1,250
Bachelor's degree or higher	14.9%
Average commute (minutes)	29.2
Households with kids under 18	27.5%
Moved in the past year	7.8%
Below the poverty line	8.5%
Broadband internet	91.1%
Speak a non-English language at home	2.1%

Household income

% of households	Value
<$10K	4.7%
$10–15K	1.6%
$15–25K	7.4%
$25–35K	6.7%
$35–50K	7.5%
$50–75K	16.3%
$75–100K	14.3%
$100–150K	25.0%
$150–200K	7.1%
$200K+	9.4%

Age

% of all residents	Value
<10	14.4%
10–19	9.7%
20–24	3.1%
25–34	14.8%
35–44	9.2%
45–54	10.5%
55–64	14.8%
65–74	15.5%
75+	8.0%

Tenure

% of housing units	Value
Owned, with mortgage	51.6%
Owned outright	28.8%
Rented	14.8%
Vacant	4.8%

Type of building

% of housing units	Value
Detached house	78.2%
Townhome	0.4%
2–4 units	2.7%
5–19 units	1.3%
20+ units	2.8%
Mobile / other	14.7%

Businesses in 98611

160 business establishments with 902 employees (ZIP Codes Business Patterns 2023).

Construction: 32
Accommodation and Food Services: 22
Retail Trade: 18
Agriculture, Forestry, Fishing and Hunting: 17
Other Services (except Public Administration): 16
Professional, Scientific, and Technical Services: 11
Administrative and Support and Waste Management and Remediation Services: 8
Transportation and Warehousing: 7

EDDM carrier routes

98611 has 8 USPS carrier routes with 3,918 residential and 51 business mailboxes. Open the EDDM route map.

Carrier routes in 98611

98611 has 8 USPS carrier routes (8 rural (R)) with 3,918 residential and 51 business mailboxes. Routes range from 468 homes (R007) to 529 homes (R003); the median route has 483 homes. The Census counted 3,539 households in 98611 (2020–2024 average); USPS counts current mailboxes, including new and vacant homes.

Homes per route	Routes
1–249	0
250–499	6
500–749	2
750–999	0
1,000–1,499	0
1,500+	0

Best routes in 98611 for…

Most businesses

For B2B offers: office supplies, cleaning, IT, catering and commercial services.

Route R003 — USPS business mailboxes 20, 529 homes
Route R007 — USPS business mailboxes 12, 468 homes
Route R008 — USPS business mailboxes 9, 505 homes
Route R004 — USPS business mailboxes 3, 497 homes
Route R001 — USPS business mailboxes 3, 483 homes

Select these 5 routes on the route map

Every carrier route in 98611

Route	Type	Homes	Businesses	Est. median income	Est. owners	Est. families with kids	Est. moved in past year
R001	Rural	483	3	$84,586	—	—	—
R002	Rural	473	0	$107,629	—	—	—
R003	Rural	529	20	$57,064	—	—	—
R004	Rural	497	3	$95,409	—	—	—
R005	Rural	482	2	$121,983	—	—	—
R006	Rural	481	2	$95,026	—	—	—
R007	Rural	468	12	$87,539	—	—	—
R008	Rural	505	9	$85,210	—	—	—

Income, owners, families and movers are estimates for each route (how we estimate them); mailbox counts are current USPS figures. Open 98611 on the EDDM route map.

How route demographics are estimated

Mailbox counts come from USPS; demographics are estimates

The number of homes and businesses on each carrier route is the current USPS EDDM count. The Census Bureau does not publish figures for carrier routes, so income, homeownership, ages, families, movers and housing age on a route are EDDM2GO estimates built from Census block groups (neighborhood areas of roughly 600 to 3,000 people).

How a route gets its figures: the block-group length-share method

We trace each route's streets every 25 meters and record which block group each stretch falls in. The route's homes are spread along its streets in proportion to length, so a route with 60% of its street length in one block group is assumed to have 60% of its homes there. Each block group then contributes its Census counts in proportion to the share of its housing units that sit on the route (capped at the whole block group). Medians are recalculated from the combined income, home-value and age brackets, the way the Census Bureau computes them, not averaged.

Margins of error

Census survey figures carry a margin of error at 90% confidence; we carry it through the calculation and show it as ±. Our margins treat the route-to-block-group split as exact, so the real uncertainty is larger. Routes with fewer than 100 estimated households, large margins, or streets we could not place are flagged.

Different years

USPS mailbox counts are current. Census figures are 5-year averages for 2020–2024, so a new subdivision may have more homes on the route today than the Census counted. Use the route figures to compare routes with each other, not as an exact head count.

Why some routes show identical figures

Two routes that run through the same block group get the same percentages and medians, because the Census publishes one set of figures for the whole block group. Their mailbox counts still differ, and those are exact.

Route and mailbox counts: USPS EDDM route data. Route demographics: EDDM2GO estimates from U.S. Census Bureau American Community Survey 5-year block-group data (2020–2024) and 2024 cartographic block-group boundaries. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.

Nearby ZIP codes

98645 (7 mi)
98593 — Vader city, WA (8.5 mi)
98581 — Ryderwood CDP, WA (8.8 mi)
98632 — Longview city, WA (10.4 mi)
98626 — Kelso city, WA (11 mi)
98591 — Toledo city, WA (12 mi)
98596 — Winlock city, WA (13.2 mi)
98609 (16.2 mi)

Areas that include 98611

Where it ranks

Mail every home in 98611

Route counts on this page price as Full Service 6.5 × 9 postcards: we print, bundle by carrier route and hand the mailing to USPS. Prefer to take it to the Post Office yourself? Print only costs less and you pay postage at drop-off.

EDDM guides

ZIP code statistics describe the Census ZIP Code Tabulation Area (ZCTA) 98611, which approximates the USPS ZIP code area. Census figures: American Community Survey 5-year estimates, 2020–2024.

Frequently asked questions

What city is 98611 in?: 98611 is a Castle Rock, WA mailing address. By land area, 2% lies inside Castle Rock; the rest is outside any Census-defined city or community.
What county is 98611 in?: 98611 is in Cowlitz County.
What is the population of 98611?: About 9,302 people (±986), according to the Census Bureau's American Community Survey 5-year estimates for 2020–2024. The 2020 Census counted 10,165.
What is the median household income in 98611?: $86,322 (±$12,746), compared with $98,141 for Washington as a whole. Half the households in the ZIP code earn more and half earn less.
How many carrier routes and mailboxes are in 98611?: 8 USPS carrier routes with 3,918 residential and 51 business mailboxes (3,969 in all), from the route data stored by EDDM2GO. An EDDM mailing can target any combination of these routes.
What ZIP codes are near 98611?: The closest, measured center to center: 98645 (7 mi), 98593 (8.5 mi, Vader), 98581 (8.8 mi, Ryderwood), 98632 (10.4 mi, Longview), 98626 (11 mi, Kelso) and 98591 (12 mi, Toledo).

This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.