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County ZIP codes · Montana · FIPS 30049

Lewis and Clark County, MT ZIP Codes

Lewis and Clark County, Montana has 16 ZIP codes (Census 2020 ZCTA-county file; GeoNames postal codes, October 2026): 12 residential and 4 for PO boxes or a single organization. 11 of the residential ones lie mainly in Lewis and Clark County and 1 mainly in a neighboring county; 3 cross the county line. Median household income ranges from $72,290 in 59601 to $92,985 in 59602 (Census Bureau, ACS 2020-2024).

  • ACS2020-24
  • Census2020

Where are the ZIP codes of Lewis and Clark County?

59410 · Augusta: $42k59421 · Cascade: $78k59601 · Helena: $72k59602 · Helena: $93k59625 · Helena: –59633 · Canyon Creek: –59635 · East Helena: $84k59636 · Fort Harrison: –59639 · Lincoln: $58k59640 · Marysville: $99k59648 · Wolf Creek: $66k594105963959648594215960259633596015963559410 · Augusta: $42k59421 · Cascade: $78k59601 · Helena: $72k59602 · Helena: $93k59625 · Helena: –59633 · Canyon Creek: –59635 · East Helena: $84k59636 · Fort Harrison: –59639 · Lincoln: $58k59640 · Marysville: $99k59648 · Wolf Creek: $66k594105963959648594215960259633596015963559410 · Augusta: $42k59421 · Cascade: $78k59601 · Helena: $72k59602 · Helena: $93k59633 · Canyon Creek: –59635 · East Helena: $84k59636 · Fort Harrison: –59639 · Lincoln: $58k59640 · Marysville: $99k59648 · Wolf Creek: $66k5941059639596485942159602596335960159635
The residential ZIP codes of Lewis and Clark County (whole outlines, including the parts in neighboring counties), shaded by median household income in national fifths (ACS 2020-2024). <$54.1k$98.1k+no figure

Source: U.S. Census Bureau, 2020 ZCTA cartographic boundaries; ACS 2020-2024 5-year estimates (B19013).

How different are its ZIP codes?

They carry 9 postal town names.

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates (B19013).

All 12 residential ZIP codes in Lewis and Clark County

11 ZIP codes lie mainly in Lewis and Clark County; 1 more reaches into it from a neighboring county and follows the first table.

Residential ZIP codes mainly in Lewis and Clark County, largest first; "In this county" is the share of the ZIP's land in the county
In this county
59601 Helena 31,728 244 $72k $387k 100%
59602 Helena 30,754 59 $93k $409k 100%
59635 East Helena 8,292 104 $84k $396k 38%
59639 Lincoln 1,021 2 $58k $372k 100%
59625 Helena 663 7,286 – – 100%
59410 Augusta 520 0 $42k $259k 98%
59648 Wolf Creek 486 1 $66k $264k 100%
59633 Canyon Creek 272 1 – $414k 100%
59640 Marysville 160 8 $99k $288k 100%
59636 Fort Harrison 32 10 – – 100%
59623 Helena no residents 0 – – 100%

Partly in Lewis and Clark County

Residential ZIP codes mainly in another county that reach at least 1% into Lewis and Clark County, by their share here
In this county
59421 Cascade 2,069 3 $78k $378k 4%

Download the 16 ZIP codes as CSV

Source: U.S. Census Bureau, ACS 2020-2024 5-year estimates; county shares by land area (Census 2020 ZCTA-county relationship file).

Which ZIP codes cross the county line?

3 ZIP codes of Lewis and Clark County extend into another county. A ZIP code follows mail routes, not county borders.

Share of each ZIP code's land in Lewis and Clark County and in the neighboring counties
ZIPIn Lewis and ClarkElsewhere
5963538%Jefferson County 36%; Broadwater County 26%
594214%Cascade County 96%
5941098%Teton County 2%

Source: U.S. Census Bureau, 2020 ZCTA-county relationship file (shares of land area).

PO Box and single-organization ZIP codes

ZIP codes in Lewis and Clark County without a residential area (GeoNames postal codes)
ZIPPostal name
59604Helena
59620Helena
59624Helena
59626Helena

Source: GeoNames postal codes (CC BY 4.0).

Which first three digits do Lewis and Clark County's ZIP codes use?

The first three digits of a ZIP code name the sectional center, the mail processing plant that sorts it. Lewis and Clark County's ZIP codes use 2 prefixes: 594 and 596.

Three-digit prefixes of Lewis and Clark County's ZIP codes, the sectional center for each (USPS labeling list L005, effective October 1, 2026) and how many of the prefix's codes are Lewis and Clark County's
PrefixSectional centerHereAll codes
594 Great Falls, MT (SCF 594) 2 64
596 Great Falls, MT (SCF 594) 14 24

Source: U.S. Postal Service, labeling list L005 (3-digit ZIP Code prefix groups, SCF sortation), effective October 1, 2026.