Lewis and Clark County
Montana · County seat: Helena · Active county or equivalent
FIPS code 30049 is Lewis and Clark County, Montana. With a population of 71,487 (2022 ACS estimate), it ranks #6 in Montana and #766 nationally. Lewis and Clark County is part of the Helena, MT. The state FIPS code for Montana is 30. This code is used in Census Bureau, BLS, EPA, HUD, and USDA federal datasets to identify this county.
County FIPS
30049
Population
71,487
2022 ACS · #766 nationally
Density
20.7/mi²
people per sq mile
Land Area
3,459
sq miles
Urban/Rural
Metro — under 250K population
RUCC 3
How This FIPS Code Works
The 5-digit FIPS code 30049 is formed by combining the 2-digit state identifier 30 (Montana) with the 3-digit county identifier 049. Together they uniquely identify Lewis and Clark County in every US federal dataset. No two counties share the same 5-digit FIPS code.
Census ACS Data for FIPS 30049
From the 2022 ACS 5-year estimates — the same values you'd retrieve by querying the Census API with county FIPS 30049.
Median Household Income
$71,967
ACS B19013_001E
Poverty Rate
9.4%
ACS B17001 (below poverty level)
Median Age
41.2
ACS B01002_001E
Metropolitan Area
Adjacent Counties (7)
Counties that share a border with Lewis and Clark County. Useful for regional analysis — these are the geographies you'd typically include when studying labor markets, commuting zones, or environmental spillovers around FIPS 30049.
Federal Datasets Using Code 30049
FIPS code 30049 appears as the county identifier in the following federal datasets. Analysts joining data across these sources use this code as the common geographic key.
Using FIPS Code 30049 in Code
Common patterns for querying federal datasets by this county's FIPS code. The leading zeros are significant — always treat FIPS codes as strings, not integers.
import requests
url = "https://api.census.gov/data/2022/acs/acs5"
params = {
"get": "NAME,B19013_001E,B01003_001E",
"for": "county:049",
"in": "state:30",
"key": "YOUR_CENSUS_API_KEY",
}
r = requests.get(url, params=params)
data = r.json() # [[header...], [Lewis and Clark County, Montana, income, pop, ...]-- 5-digit combined FIPS (state + county)
SELECT * FROM your_table WHERE county_fips = '30049';
-- Some datasets store state and county separately
SELECT * FROM your_table
WHERE state_fips = '30'
AND county_fips = '049';
-- ⚠ Never cast to integer — leading zeros are lost:
-- county_fips = 30049 is WRONG for this countylibrary(tidycensus)
get_acs(
geography = "county",
variables = c(income = "B19013_001E", pop = "B01003_001E"),
state = "30",
county = "049",
year = 2022
)ZIP Codes in Lewis and Clark County
ZIP codes do not align perfectly with county boundaries — a single ZIP code can span multiple counties, and a county can contain parts of many ZIP codes. The ratios below (from the Census 2020 ZCTA relationship file) show the land area share of each ZCTA that falls within Lewis and Clark County. Why FIPS ≠ ZIP →
| ZIP Code | % in county |
|---|---|
| 59648 | 100.0% |
| 59636 | 100.0% |
| 59639 | 100.0% |
| 59640 | 100.0% |
| 59601 | 100.0% |
| 59602 | 100.0% |
| 59623 | 100.0% |
| 59625 | 100.0% |
| 59633 | 100.0% |
| 59410 | 97.6% |
| 59635 | 38.1% |
| 59421 | 4.5% |