ZIP code 57421 covers Sunset Colony, South Dakota in Marshall County. This area is served by 15 utility providers across 3 categories. The average residential electricity rate here is 10.1¢/kWh.
Estimated monthly utility costs
$510/month
Cost estimates from U.S. Census ACS 5-year data · Shorter bar = lower cost
Electric
Water
Internet
Nearby ZIP codes
Frequently asked questions
How do I set up utilities when moving to 57421?
Contact each provider separately before your move-in date. Start with electric (NorthWestern Energy - (SD)) since those typically need a few business days to activate. Water and sewer are often handled with one call to your local utility. Set up internet last since it may require an installation visit.
How much do utilities cost per month in 57421?
Total estimated monthly costs are around $509, which is about $126 more than the national average. Electricity is the biggest expense at roughly $225/month. Natural gas runs about $225. Water and sewer combined are around $60. Costs vary by home size, usage, and season. Estimates from U.S. Census ACS data.
Is electricity expensive in 57421?
No — electricity in Sunset Colony, SD costs about 33% less than the national average. Compared to South Dakota overall, rates here are about 18% lower. Based on 2023 NREL residential electricity rate data.
What internet providers are available in 57421?
Sunset Colony, SD has broadband coverage. Providers include T-Mobile (Fixed Wireless up to 100 Mbps), Venture Communications Cooperative Inc (Fiber up to 1,000 Mbps), Verizon (Fixed Wireless up to 50 Mbps). Availability varies by street address. Based on FCC Broadband Data Collection filings.
What county is 57421 in?
ZIP code 57421 is in Marshall County, South Dakota.
Disclaimer: Provider information is sourced from federal databases including HIFLD, EPA SDWIS, FCC Broadband Data, and EIA-861. Utility cost estimates are from the U.S. Census Bureau American Community Survey 5-Year Estimates. Electric rates are based on 2023 NREL data. Coverage areas are approximate and may not reflect recent changes. Please verify directly with your provider.
Data sources: U.S. Census Bureau, NREL, EIA-861, HIFLD, EPA, FCC. Last updated: April 2026.