Sully County

Sully County, South Dakota — key demographics

Population size

• 1,466 (2020 Decennial Census)

Age

• Median age: ~43 years (ACS 2019–2023)
• Under 18: ~25%
• 65 and over: ~20%

Gender

• Male: ~51%
• Female: ~49%

Race and ethnicity (ACS 2019–2023)

• White alone: ~95%
• American Indian and Alaska Native alone: ~2%
• Two or more races: ~2–3%
• Black or African American alone: <1%
• Asian alone: <1%
• Hispanic or Latino (any race): ~2%

Households (ACS 2019–2023)

• Total households: ~635
• Average household size: ~2.3
• Family households: ~66% of households
• Married-couple households: ~57% of households
• Households with children under 18: ~30%
• Nonfamily households: ~34%
• Owner-occupied housing rate: ~85%

Insights

• Very small, predominantly White rural county with a modestly older age profile, high share of family and owner-occupied households, and small average household size.

Sources: U.S. Census Bureau, 2020 Decennial Census; American Community Survey 2019–2023 5-year estimates.

Sully County, SD snapshot

• Population/density: 1,446 residents (2020 Census), roughly 1.4 people per square mile—one of South Dakota’s least-dense counties.
• Estimated email users: ~1,100–1,200 residents (≈76–83% of total; ≈92–96% of adults), reflecting near-universal email use among internet-connected adults.
• Age distribution of email users (estimated share of users): • Under 18: ~10% (younger teens adopt email later) • 18–34: ~22% • 35–64: ~50% • 65+: ~18% (senior adoption high but below prime working ages)
• Gender split among email users: approximately 51% male, 49% female, mirroring the county’s slight male majority and minimal gender gap in email adoption.
• Digital access and trends: • Household internet subscriptions are in the mid‑80% range (ACS-based rural SD pattern), with strong adoption in/near Onida and gaps on dispersed farms/ranches. • Mobile connectivity covers population centers and corridors; roughly 10–15% of households are mobile‑only for home internet in line with rural SD norms. • Fixed broadband is a mix of fiber/cable in town and fixed wireless or satellite in outlying areas; speeds and reliability decrease with distance from town sites.

Implication: Email is a routine channel for nearly all working‑age adults, with slightly lower penetration among seniors and remote households.

Mobile phone usage in Sully County, South Dakota — user estimates, demographics, and infrastructure, with county-versus-state contrasts

Snapshot

• Population base: 1,446 (2020 Census). Extremely low density (~1.4 persons per square mile), with population centered in and around Onida and scattered rural homesteads.
• Age profile: Older than the state overall, which materially affects smartphone adoption and the share of “cellular-only” home internet use.

User estimates (modeled from 2020 Census population and Pew Research 2024 age-specific adoption rates)

• Adults (18+): ≈1,100
• Adult mobile phone users (any cellphone): ≈1,060
• Adult smartphone users: ≈920
• Total mobile users including teens (12–17): ≈1,160 Explanation of method: These totals are derived by weighting age brackets typical of Sully’s rural profile against national cell/smartphone ownership by age. They closely track ACS patterns for rural counties in South Dakota where nearly all adults have a mobile phone but smartphone prevalence is pulled down by a comparatively large 65+ cohort.

Demographic breakdown of usage

• By age (adults):
  • 18–29: ~200 adults; ~190 smartphone users (very near-universal smartphone adoption)
  • 30–49: ~350 adults; ~330 smartphone users
  • 50–64: ~290 adults; ~240 smartphone users (noticeable drop versus younger cohorts)
  • 65+: ~260 adults; ~160 smartphone users (lowest smartphone share; more basic/flip-phone use)
• By geography within the county:
  • Highest signal quality and 5G availability in and near Onida and along US‑83/SD‑34
  • Mixed LTE/limited 5G and occasional dead zones in outlying ranch/farm areas, especially away from highway corridors and along the Missouri River breaks
• By household connectivity behavior:
  • Higher reliance on “cellular-only” home internet (mobile hotspot or phone tethering as the primary connection) than the South Dakota state average, reflecting fiber’s concentration in Onida and the patchier availability of wired broadband in the countryside
• By occupation/sector:
  • Above-average adoption of mobile data in agricultural operations (equipment telemetry, field ops, and market/comms), but with uneven performance tied to distance from macro towers; some farms supplement with private CBRS/fixed wireless where terrain permits

Digital infrastructure and performance

• Networks present: AT&T, Verizon, and T-Mobile all operate in the county; low-band spectrum (e.g., 600/700 MHz) carries most coverage in the open range, with mid-band 5G mainly along travel corridors and in town.
• Coverage pattern: A sparse macro-tower grid typical of very low-density counties; best service clusters along US‑83 and in Onida. LTE is the baseline countywide; 5G (particularly mid-band) is available but not continuous outside the main corridors.
• Backhaul and fixed broadband context: Fiber and high-capacity backhaul are strongest in Onida (served by regional/co-op providers). Outside town limits, many locations depend on fixed wireless or satellite. This mix raises the share of households leaning on cellular for primary connectivity compared with the statewide profile.
• Reliability: Voice/text reliability is generally strong on corridor routes and in town; data rates and 5G availability degrade quickly with distance from towers, contributing to a wider rural performance gap than the state average.

How Sully County differs from South Dakota overall

• Lower smartphone penetration among adults, driven by a larger 65+ share; total adult smartphone adoption is a few points below the statewide rate.
• Higher incidence of cellular-only home internet usage, reflecting limited wired options outside Onida; this is notably above the state share.
• Greater spatial variability in service quality: more frequent dead zones and larger LTE-to-5G performance swings away from highways than typical statewide.
• Heavier dependence on low-band coverage for reach, which constrains average mobile data speeds relative to South Dakota’s metro and micropolitan counties.

Sources and methods

• Baseline population: U.S. Census 2020 (Sully County = 1,446).
• Adoption rates: Pew Research Center (2024) smartphone and cellphone ownership by age; applied to a rural-weighted age distribution consistent with ACS 5‑year county profiles.
• Infrastructure characterization: FCC Broadband/Data Collection filings and carrier public coverage disclosures for South Dakota, combined with local provider footprints.

Sully County, SD social media snapshot (2025)

Context and user base

• Population: ~1,450 (2020 Census). Rural, older-leaning age profile.
• Broadband access: roughly 78–85% of households (ACS, SD rural norms).
• Modeled adult social-media participation: 65–75% of residents use at least one platform monthly.

Most-used platforms (share of adults using monthly; modeled for Sully County from Pew 2024 + rural age mix)

• YouTube: 75–82%
• Facebook: 68–75%
• Facebook Messenger: 60–70%
• Instagram: 30–40%
• Pinterest: 28–35% (women-heavy)
• Snapchat: 22–30%
• TikTok: 18–25%
• X (Twitter): 12–18%
• LinkedIn: 10–15%
• Reddit: 10–15%
• WhatsApp: 8–12%
• Nextdoor: <5%

Age-group usage patterns (share within each age band; modeled)

• Teens (13–17): YouTube ~95%; Snapchat 75–85%; TikTok 65–75%; Instagram 60–70%; Facebook 30–40%.
• 18–29: YouTube 90%+; Instagram 70–80%; Snapchat 55–65%; TikTok 50–60%; Facebook 55–65%.
• 30–49: Facebook 70–80%; YouTube 80–90%; Instagram 40–50%; Snapchat 20–30%; TikTok 20–30%; Pinterest 35–45% (women).
• 50–64: Facebook 75–85%; YouTube 70–80%; Pinterest 30–40% (women); Instagram 20–30%; TikTok 10–20%.
• 65+: Facebook 60–70%; YouTube 55–65%; Instagram 10–20%; TikTok 5–10%.

Gender breakdown of user bases (local share by platform; modeled)

• Facebook: ~55% women / 45% men
• Instagram: ~60% women / 40% men
• Pinterest: ~75% women / 25% men
• Snapchat: ~60% women / 40% men
• TikTok: ~60% women / 40% men
• YouTube: ~45% women / 55% men
• X (Twitter): ~35% women / 65% men
• Reddit: ~30% women / 70% men
• LinkedIn: ~45% women / 55% men
• WhatsApp: ~45% women / 55% men

Behavioral trends

• Facebook is the community hub for county news, school sports, church and 4‑H updates, auctions, storm information, and event coordination; Marketplace is heavily used for farm/ranch equipment and local resale.
• YouTube is preferred for practical video: ag equipment repair, how‑to content, weather briefings, hunting/fishing, and local sports highlights.
• Messaging is dominated by Facebook Messenger and Snapchat; SMS remains common among older adults.
• Engagement spikes around school events, severe weather, planting/harvest, and hunting seasons; daily peaks occur before work (6–8 a.m.), lunch (11:30 a.m.–1 p.m.), and evenings (7–10 p.m.).
• Trust is local: posts from known people, schools, churches, county offices, and recognizable businesses outperform generic or out‑of‑area promotions.
• Platform roles: Facebook for reach/community; Instagram for youth/parents and local businesses; TikTok for teens/young adults and short-form trends; YouTube for searchable utility; X for weather/sports/state agency updates; LinkedIn is niche; Nextdoor has minimal footprint.

Method note Figures are modeled for Sully County by applying Pew Research Center’s 2024 U.S. platform adoption rates to a rural Great Plains age mix and South Dakota ACS broadband adoption. County-level platform registries are not published, so values are best-available estimates suitable for planning.