Internet Providers in 57799

With 6 carriers competing, Spearfish, SD (57799) is a well-served market where subscribers benefit from competitive pricing and frequent promotional offerings. ZIP 57799 (Spearfish, SD) has a highly concentrated broadband market (HHI: 39,588) where Starlink dominates with 100% coverage reach — 0 percentage points ahead of the next-largest provider, HughesNet at 100%. In highly concentrated markets, consumers typically see fewer promotional offers and less pressure on the leading provider to invest in network upgrades. The remaining 4 providers in ZIP 57799 (Spearfish, SD) cover a fraction of addresses, limiting their competitive impact. Research from the FCC shows that markets with one dominant provider average higher monthly costs compared to markets with two or more meaningfully overlapping competitors.

Based on granular FCC coverage data for your specific area, 7 providers have infrastructure near ZIP 57799 — more than the 6 reported at the metro level.

In the immediate vicinity of ZIP 57799, verified infrastructure supports fiber speeds up to 1 Gbps, cable speeds up to 2 Gbps.

The Herfindahl-Hirschman Index (HHI) for this ZIP code is 39,588, classifying it as a highly concentrated market under U.S. Department of Justice guidelines. A highly concentrated market means one or two providers control most of the coverage, which can limit competitive pricing for consumers.

Fiber-optic coverage here reaches 68% of addresses — 11 points above the national average of 57%. Above-average fiber availability gives residents more choices among the fastest connection type and typically drives cable providers to offer more competitive pricing in response. Fiber-optic coverage here is above average and growing. Nationally, fiber availability has expanded by roughly 8 percentage points per year since 2022, with ISPs like AT&T, Frontier, and Google Fiber leading the rollout of high-speed internet.

Fiber internet is available from CenturyLink, with 68% fiber coverage — significantly above the national average of 57%. Fiber delivers symmetrical upload and download speeds — a key advantage for households with multiple remote workers, video conference participants, or content creators who upload large files. Nationally, fiber represents the fastest-growing broadband technology segment, expanding at roughly 8 percentage points of coverage per year. Fixed wireless internet — including 5G home internet services — is available from T-Mobile and Verizon 5G Home, reaching 70% of addresses (well above the national fixed wireless average of 32%). Fixed wireless offers a no-installation alternative that is increasingly competitive with cable for everyday internet use, with speeds typically ranging from 50-300 Mbps download. Unlike satellite, fixed wireless delivers lower latency (20-40 ms), making it viable for video conferencing and gaming. Satellite internet (Starlink, HughesNet, Viasat) reaches addresses that wired broadband can't. Starlink's low-Earth-orbit (LEO) technology delivers 20-60 ms latency — a major improvement over geostationary services at 600+ ms — making it a practical choice for rural households without fixed-line options.

Residents of ZIP code 57799 can choose from plans starting at $45/mo (T-Mobile Rely Home Internet GEO TE, 150 Mbps download) up to 527 Mbps (CenturyLink Simply Unlimited 500 Mbps at $50/mo). Across all 12 plans available, the median price point offers a balance of speed and affordability for typical household needs.

The technology mix in 57799 includes 1 fiber provider (17% of options), 2 fixed wireless/5G providers. Fiber optic connections deliver the fastest and most reliable performance with symmetric upload and download speeds, making them ideal for remote work, gaming, and 4K streaming.

South Dakota received $208 million in federal BEAD funding. The South Dakota GOED Broadband is currently in the challenge phase, which means providers and communities can dispute the FCC broadband maps that determine which locations qualify for funding — a critical step before deployment grants are awarded. The Affordable Connectivity Program (ACP) previously provided up to $30/month subsidies for eligible households, though federal funding expired in 2024. Some providers continue offering voluntary low-income discounts.

Market data is based on the FCC Broadband Data Collection (December 2024). Actual coverage and plan availability may vary by specific address within ZIP code 57799.

Technology Availability

Fiber-optic internet is available from 1 provider (CenturyLink), with the highest fiber coverage reaching 68% of addresses. 2 fixed wireless or 5G home internet options are available. satellite internet serves as a backup for addresses outside wired coverage areas. The technology mix in Spearfish determines the range of speeds and prices residents can access for home internet service.

Pricing Overview

Internet plans in Spearfish range from $45/month to $129.99/month, with an average of $78/month — $13/month above the national average of $65/month. Fiber plans average $52/month locally, compared to the national fiber average of $60/month. The most affordable option is T-Mobile starting at $45/month for 150 Mbps speeds. At the top end, HughesNet's 25 Mbps plan costs $129.99/month — best suited for large households or home offices needing maximum bandwidth. Residents of SD should compare at least 2-3 providers before committing, as pricing varies significantly by plan tier and technology type.

Market Competition

Despite having 6 providers, Spearfish's broadband market is highly concentrated — Starlink controls 100% of available coverage. In concentrated markets like this, consumers often see fewer promotional offers and slower infrastructure investment compared to competitive metro areas.

Speed Options

Internet speeds in Spearfish range from 12 Mbps to 527 Mbps. The fastest available plan is CenturyLink's 527 Mbps fiber service at $50/month. At 527 Mbps, the top-tier plans support 4K streaming on multiple devices simultaneously, responsive online gaming, and fast download of large files. For most households, 398 Mbps plans from AT&T offer the best balance of speed and cost for everyday use.

Our Recommendation

For most Spearfish residents, we recommend starting with fiber internet if available at your address — CenturyLink's 527 Mbps plan at $50/month offers the best combination of speed and value. Budget-conscious households should consider T-Mobile at $45/month as the most affordable option. Remote workers should prioritize CenturyLink's fiber service for its symmetrical upload speeds, which far exceed cable alternatives for video conferencing and cloud backups. Gamers should consider CenturyLink's 527 Mbps fiber plan — fiber provides the lowest latency (typically 5-15 ms) for competitive online gaming. For households of 4+ people with multiple connected devices, CenturyLink's 527 Mbps plan at $50/month provides enough bandwidth for simultaneous streaming, gaming, and video calls. Always verify availability at your exact address, as coverage can vary block by block in Spearfish.