Museums, Historical Sites, and Similar Institutions (U.S.) — NAICS 7121

An investor's rollup primer. NAICS (the North American Industry Classification System) code 7121 is the four-digit industry group that gathers America's museums, historic places, zoos, aquariums, botanical gardens, and nature preserves under one heading. This page does not research the sector from scratch — it synthesizes the four already-written child primers and adds this level's own ground-truth federal statistics. Its distinctive value is the contrast across the four children: which is biggest, which is growing, who owns them, and how — if at all — you can invest.

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1. Overview

NAICS 7121 is the "look, learn, and preserve" corner of the leisure economy: places you visit to see art, history, living animals and plants, or protected nature. Four industries sit inside it — museums; historical sites; zoos and botanical gardens; and nature parks. They share three defining traits that shape every investment question that follows:

1. They are overwhelmingly nonprofit or government, not corporate. The marquee names — the Smithsonian, the National Park Service (NPS), San Diego Zoo, Colonial Williamsburg, the Bronx Zoo, the Metropolitan Museum — are tax-exempt charities under Internal Revenue Code section 501(c)(3) or units of federal, state, or city government. None issues stock. [1][4][5][7]
2. There is essentially no pure-play stock to buy in any of the four. Public-market investors reach the theme only through diversified proxies; the genuine equity is private and mostly small or family-owned. The one child with real listed proxies is zoos-and-aquariums, and even those are theme-park companies with an animal overlay, not clean plays. [9][10][11]
3. The federal "business" statistics undercount the true footprint — badly and systematically — because government-run establishments and volunteer-only operations fall outside the surveys. This caveat applies to all four children and to the group. [22]

The result is a large, culturally central, near-atomistic field where, for the institutions that dominate it, the investor's natural role is philanthropic, not financial — and where the real money is made in the financing and services around these places rather than in owning them.

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2. What's inside — the four children and how they differ

The four industries look similar from the outside (place-based, mission-driven, admissions-plus-donations) but differ sharply in size, labor intensity, ownership, and how an investor can touch them. Shares below are of this level's receipts (2022 Economic Census); the employment column is each child's share of the group's 154,570 paid employees. [1][2]

The three contrasts that matter most:

• Museums are the anchor; zoos are the workhorse. Museums are two-thirds of the group's establishments and roughly 60% of its receipts and jobs — remove them and the group shrinks by more than half. But zoos and aquariums are far more labor- and capital-intensive per site: they employ about 55 people per establishment versus 17 for museums and ~10–11 for historical sites and nature parks, because animals must be fed, housed, and cared for around the clock. That is why zoos carry 28% of the group's jobs on under 10% of its establishments — and why they are the child where operating economics (and listed proxies) actually exist. [1][7]
• The tail is a financing-and-land story, not an operating one. Historical sites and nature parks are each only ~6% of receipts and are the most government-dominated. Value there sits not in running the landmark but in the financial rails around it: the Historic Tax Credit and adaptive-reuse real estate for historic sites; concession contracts and conservation easements for nature parks. [14][15][18]
• Ownership converges, investability diverges. All four are nonprofit-and-government at the core, but the route in differs by child: immersive venture/PE (museums), listed attraction proxies and aquarium PE (zoos), tax-credit and real-estate finance (historic sites), and real-asset/conservation finance (nature parks). One theme, four different playbooks.

Scope and boundaries (briefly). In scope: art/science/history/children's museums, planetariums, halls of fame (71211); battlefields, forts, historic houses and ships, pioneer villages (71212); zoos, aquariums, aviaries, arboreta, botanical gardens (71213); wildlife sanctuaries, nature centers, show caves, and national parks (71219). Adjacent codes that are not here: amusement and theme parks (NAICS 713110), historic hotels (Accommodation, NAICS 721), and retail art galleries. [3] Each child primer maps its own boundaries in full.

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3. Size (this level's rollup figures)

These are the Histometrics ground-truth federal figures for NAICS 7121. They stitch two vintages together — 2022 Economic Census for firms and receipts, 2023 County Business Patterns (CBP) for headcounts and payroll — so they are not a single-year income statement.

From these: the average establishment runs about 19 employees, the average firm books roughly $2.9 million in annual receipts, and average pay is near $45,600 per worker — modest, reflecting many part-time, seasonal, and mission-driven roles. (CR4/CR8 = combined revenue share of the largest 4/8 firms; HHI = a standard concentration index that runs to 10,000, where anything under 1,500 is "unconcentrated.")

How the children add up. Establishments and employees reconcile to the level exactly (5,480 + 1,120 + 781 + 797 = 8,178 establishments; 91,534 + 11,468 + 42,708 + 8,860 = 154,570 employees), and payroll and receipts reconcile within rounding. The one figure that does not sum cleanly is the firm count — the four children total about 7,488 firms versus the group's 7,436 — because a company operating in more than one of these industries is counted in each child but only once at the group level. [1][2]

Undercount caveat — large and material at every level here. Two structural gaps pull these business figures below the field's true footprint, and both are bigger in NAICS 7121 than in most industries:

• Government and university institutions are largely excluded. The Economic Census omits government-owned establishments, and CBP covers only employer establishments — yet governments own most of America's best-known historic sites, nature parks, and many zoos, and the Smithsonian alone runs on a budget above $1 billion. [7][22]
• Volunteer-only and non-employer operations have no paid-employee establishment to count. Federal grant-maker IMLS (the Institute of Museum and Library Services) counts roughly 35,000 active museums across all disciplines, against the ~5,480 paid-employer museums here; the Land Trust Alliance counts about 1,281 land trusts backed by an estimated 234,000 volunteers, many with no payroll. [4][15]

For scale on what is left out, industry bodies size the fuller picture far above the ~$21.8 billion of surveyed receipts: the American Alliance of Museums (AAM) puts museums alone near $50 billion of GDP (gross domestic product), and the Association of Zoos and Aquariums (AZA) reports its accredited members generate more than $22.5 billion in annual U.S. economic activity and support nearly 200,000 jobs. [5][7] Treat those as network benchmarks, not measures of NAICS 7121 revenue. Note also what these tables do not contain: attendance, endowment assets, donations, debt, or profitability — none should be inferred from them.

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4. Investable universe (where value concentrates across the children)

For a public-market investor this level is close to a blank page, and the blankness is uneven across the four children:

• Zoos and botanical gardens (71213) hold the only listed proxies — and even these are mixed leisure/attraction businesses, not pure plays: United Parks & Resorts (NYSE: PRKS), Parks! America (OTCQX: PRKA), and Six Flags (NYSE: FUN). They give theme-park economics with an animal-collection overlay, not zoo economics. The genuine for-profit equity clusters in aquariums — better unit economics than land-and-animal-heavy zoos — and is almost entirely private (operators such as Herschend, Landry's, and Ripley's). [7][9][10][11]
• Museums (71211) have no U.S.-listed pure-play; the largest for-profit operator, Merlin Entertainments (Madame Tussauds), was taken private in 2019. The live private seam is the for-profit immersive-experience segment (e.g., Meow Wolf) reachable through venture or private equity. [12][13]
• Historical sites (71212) offer only indirect exposure — the banks that syndicate the federal Historic Tax Credit (HTC) and developers doing adaptive reuse of National Register buildings. [14]
• Nature parks (71219) route through concession and hospitality operators on public land, experiential real estate, and conservation-grade land itself. [16][18]

Across all four, the largest owners — the Smithsonian, NPS, the endowed nonprofit foundations, the great municipal zoos and gardens — are unbuyable by design. Value for outside capital concentrates at the edges: the for-profit fringe (immersive venues, aquariums, show caves), the financing rails (Historic Tax Credits, adaptive-reuse and experiential real estate, conservation finance), and the service vendors (ticketing, exhibit fabrication, concessions, outsourced operations). Each child primer carries the full company and owner tables.

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5. How the money works

Because most operators are charities or government units, "the money" is a revenue portfolio against high fixed costs, not a product margin — and the same four-part structure recurs across the children with different weightings:

• Earned revenue — admissions, memberships, parking, retail, food, and event rentals.
• Contributed revenue — gifts, grants, corporate sponsorship, and endowment income (a set annual draw, typically 4–6% of the endowment, that ties budgets to equity markets).
• Government support — federal, state, and municipal appropriations; heaviest in zoos (often 25–40% of an AZA-accredited zoo's operating budget) and in the government-owned historic sites and nature parks. [7]
• Subsidized financing — for historic sites specifically, the 20% federal Historic Tax Credit on rehabilitating an income-producing certified historic building, usually monetized by selling the credit to a corporate investor; and for nature land, conservation easements and emerging ecosystem-service markets (carbon credits, mitigation banking). [14][18]

The common thread is operating leverage against a fixed, asset-heavy cost base. Climate control, security, insurance, conservation, and — for zoos — round-the-clock animal care run whether or not visitors come, which is why the 2020 shutdowns were near-fatal for many institutions and why attendance, per-visitor ("per-cap") spend, and the membership base are the metrics that matter. Two structural constraints limit financial flexibility: museum collections generally cannot be sold to plug operating gaps (professional deaccessioning standards restrict it), and conservation carrying-capacity rules cap volume growth at nature sites. The for-profit fringe — immersive venues, private aquariums, show caves — follows a more familiar ticket-driven, location-based-entertainment model where EBITDA (earnings before interest, taxes, depreciation, and amortization) scales with throughput, though EBITDA overstates cash when big habitat or building projects loom. [13]

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6. Demand drivers

The four children ride the same forces, with slightly different sensitivities:

• Cultural tourism and travel — the leading swing factor for museums and historic sites; weak travel held museum attendance back in 2025. [6]
• Household discretionary income and confidence — zoos and nature parks are family "day-out" purchases, among the first cuts when budgets tighten.
• Philanthropy and wealth effects — giving and endowment draws both track equity markets, a double tailwind up and a double hit down; this sets the ceiling on the non-earned two-thirds of the nonprofit model. [7]
• Weather and seasonality — outdoor attractions (zoos, gardens, nature parks) live and die by good-weather days; first-quarter payroll running well below a quarter of the annual figure confirms the seasonal pattern. [1]
• Education demand — school field trips anchor weekday attendance across all four (roughly 55 million student museum visits a year alone). [5]
• Marquee draws and anniversaries — blockbuster exhibitions, new-building openings, a panda arrival or baby-animal season, and event catalysts such as the U.S. 250th anniversary in 2026 for founding-era historic sites. [6]
• Outdoor-recreation and "authentic-experience" trends — a multi-year rise in outdoor recreation and younger travelers seeking immersive, authentic visits favor nature parks and the for-profit immersive fringe. [17]

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7. Regulation

These institutions are lightly regulated as businesses but bound by a distinctive, child-specific web of rules — more about protection, subsidy, and stewardship than restriction:

• Tax-exempt status under IRC 501(c)(3), with unrelated-business income tax (UBIT) on some commercial activity — applies across all four. [19]
• Federal grant agencies — IMLS, the National Endowment for the Arts, and the National Endowment for the Humanities — whose support is politically exposed; a 2025 attempt to gut IMLS was reversed by a court, with grants reinstated in December 2025. [20]
• Cultural-property law for museums — NAGPRA (the Native American Graves Protection and Repatriation Act, strengthened by a 2023 final rule effective 2024) and professional deaccessioning standards. [4]
• Historic-preservation law for historic sites — the National Historic Preservation Act of 1966, the National Register of Historic Places, Section 106 review, and HTC certification. [14]
• Animal and wildlife law for zoos and aquariums — the Animal Welfare Act (enforced by USDA APHIS, the U.S. Department of Agriculture's Animal and Plant Health Inspection Service), the Endangered Species Act, and the Marine Mammal Protection Act; note that AZA accreditation is voluntary and separate from the law. [7]
• Land, environmental, and concession law for nature parks — the NPS Organic Act mandate, the concession-contract regime, and conservation-easement tax rules, where a 2024 IRS/Treasury crackdown on syndicated easements tightened penalties while leaving legitimate landowner easements deductible. [16][18]
• Accessibility — the Americans with Disabilities Act (ADA) applies to all public-accommodation sites.

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8. Consolidation

By any federal measure this is one of the least concentrated industry groups in the economy. The top 4 firms hold just 9.0% of receipts, the top 8 hold 12.1%, the top 20 hold 19.0%, and the top 50 hold 29.6%; the HHI is 31.2 — near-atomistic, roughly fifty times below the 1,500 threshold U.S. antitrust authorities treat as "unconcentrated." [2] The group is even less concentrated than any of its children (museums, the least-concentrated child, has an HHI of ~63), because pooling four fragmented industries over 7,436 firms spreads share further still.

The fragmentation is structural, not a stage awaiting a roll-up. Nonprofits do not merge to capture market share, and governments do not sell landmarks — so the classic consolidation dynamic is absent from the core. Where scale-building actually occurs is at the edges: for-profit operators rolling up aquariums and immersive venues; large banks dominating Historic Tax Credit syndication; cash-strapped cities outsourcing zoo, garden, and site operations to nonprofits or private managers under public-private partnerships (P3s); and small land trusts merging into stronger regional ones. The federal data carry no mergers-and-acquisitions series, so those transactions must be tracked one by one. [2]

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9. Risks

The children share a common risk map, with each child weighting it differently:

• Funding and market volatility — donations and endowment draws are tied to equity markets, so a downturn hits both giving and the endowment draw at once (heaviest for museums and endowed nonprofits).
• Political / public-funding risk — the 2025 IMLS episode for museums; annual NPS and Historic Preservation Fund pressure for historic sites and nature parks; municipal budgets for zoos and gardens. [20]
• Attendance fragility against fixed costs — costs cannot flex with visits; only ~45% of museums had regained 2019 attendance as of AAM's 2025 snapshot, and post-pandemic recovery is incomplete for zoos too. [6]
• Capital and deferred maintenance on aging buildings, ships, habitats, and landscapes.
• Asset-specific exposures — illiquid collections and repatriation claims (museums); animal-welfare and reputational pressure (zoos); title, easement, and community-claim constraints (historic sites and nature land); climate and biosecurity threats such as avian influenza and extreme heat (zoos and nature parks).
• Tax-policy risk — the Historic Tax Credit and conservation-easement deductions are creatures of the tax code and can be tightened (as the 2024 syndicated-easement rule showed). [14][18]
• Proxy/comparability risk — because there is no pure-play, any listed name carries only partial exposure, and the business statistics weakly match the true institutional universe.
• Fad and novelty risk on the for-profit fringe — immersive venues and attractions face novelty fatigue.

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10. How to invest & outlook

Public markets offer only indirect exposure, and only one child offers any at all. The listed proxies — United Parks & Resorts (PRKS), Parks! America (PRKA), and Six Flags (FUN) — sit in zoos-and-aquariums and are attraction companies with an animal overlay, best framed on enterprise value against normalized EBITDA while remembering that EBITDA overstates cash when major habitat or building capital looms. Analyze the relevant segment of each diversified name (visitor economics, per-cap spend, property quality, leverage) rather than applying a "museum multiple" to a conglomerate. [9][10][11]

Private markets hold the more genuine — and more child-specific — routes:

• Museums — venture/private equity in the for-profit immersive-experience segment; philanthropic capital for the nonprofit core (a social-and-tax return, not a cash yield). [13]
• Zoos and aquariums — private for-profit aquarium and attraction operators (the best private unit economics in the group), plus P3 operating contracts as a services angle. [7]
• Historical sites — owning and rehabilitating certified historic buildings for the 20% HTC (often stacked with a state credit), and adaptive-reuse real estate. [14]
• Nature parks — park concessions won by contract, conservation-grade land as a real asset, and ecosystem-service/conservation-finance strategies. [16][18]

Outlook (editor's judgment). Demand for cultural and natural experiences is durable and only mildly cyclical, but the model is under real cost pressure — rising labor, animal-care, insurance, and construction costs against incomplete attendance recovery and mounting deferred capital. Expect institutions to lean on dynamic pricing, memberships, and premium experiences to lift per-cap, and expect the P3-outsourcing and immersive-venue trends to continue. Among the children, botanical gardens look like the structural bright spot (cheaper to run than animal collections, with visitation up sharply over the past decade), the for-profit immersive segment is the genuine growth story (carrying fad and capital-intensity risk), the 2026 U.S. 250th anniversary is a near-term lift for founding-era historic sites, and conservation finance (carbon, mitigation) is turning preserved nature into a cash-flowing asset class even as a stricter IRS regime reshapes the tax-driven end. Federal-funding stability remains a live political variable across all four after the 2025 IMLS reversal. [6][7][20]

Bottom line. NAICS 7121 is a large, culturally central, near-atomistic field (~$21.8 billion in surveyed receipts, ~8,200 employer establishments, ~155,000 employees) that undercounts a far larger nonprofit-and-government footprint public markets cannot buy. Museums are the anchor, zoos the labor-and-capital workhorse and the only child with listed proxies, and historical sites and nature parks are financing-and-land stories rather than operating ones. For the institutions that dominate the group, the investor's role is philanthropic; where real capital returns exist, they are found in the for-profit fringe, the financing rails, and the service vendors around these places — never in owning the landmarks themselves. For the full, owner-by-owner detail behind each of the four, read the child primers for 71211, 71212, 71213, and 71219.

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Sources

Synthesized from the four child primers (71211 Museums, 71212 Historical Sites, 71213 Zoos and Botanical Gardens, 71219 Nature Parks). Figures in Sections 2, 3, and 8 are Histometrics ground-truth federal data for NAICS 7121; the child-level figures cited for comparison come from the corresponding child primers.

1. U.S. Census Bureau, County Business Patterns, NAICS 7121 and children (712110/712120/712130/712190), 2023 — establishments, employment, annual and Q1 payroll (Histometrics ground-truth dataset). https://www.census.gov/data/datasets/2023/econ/cbp/2023-cbp.html
2. U.S. Census Bureau, 2022 Economic Census — Concentration of Largest Firms, NAICS 7121 and children — firms, receipts, CR4/CR8/CR20/CR50, HHI (Histometrics ground-truth dataset). https://data.census.gov/table/ECNSIZE2022.EC2200SIZECONCEN
3. U.S. Census Bureau, 2022 NAICS definitions — 7121 and constituent industries 71211/71212/71213/71219, with cross-references. https://www.census.gov/naics/?input=7121&year=2022
4. Institute of Museum and Library Services, "Government Doubles Official Estimate: There Are 35,000 Active Museums in the U.S."; NAGPRA 2023 final rule. https://www.imls.gov/news/government-doubles-official-estimate-there-are-35000-active-museums-us
5. American Alliance of Museums / Oxford Economics, Museum Facts & Data (~$50B GDP; 55M student visits; 76% of leisure travelers). https://www.aam-us.org/programs/about-museums/museum-facts-data/
6. American Alliance of Museums, 2025 Annual National Snapshot of United States Museums (2025). https://www.aam-us.org/2025/11/11/2025-annual-national-snapshot-of-united-states-museums/
7. Association of Zoos and Aquariums, Zoo and Aquarium Statistics and Conservation Funding ($22.5B economic activity; ~200,000 jobs; 25–40% government support). https://www.aza.org/zoo-and-aquarium-statistics
8. American Public Gardens Association, Benchmarking (~600 gardens; visitation up sharply since 2014). https://www.publicgardens.org/benchmarking/
9. United Parks & Resorts Inc. (NYSE: PRKS), 2025 Form 10-K, SEC EDGAR. https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001564902&type=10-K
10. Parks! America, Inc. (OTCQX: PRKA), 2024 Form 10-K, SEC EDGAR. https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001297937&type=10-K
11. Six Flags Entertainment Corporation (NYSE: FUN), 2025 Form 10-K, SEC EDGAR. https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0001999001&type=10-K
12. Merlin Entertainments — 2019 take-private by Blackstone, KIRKBI, and CPP Investments (Madame Tussauds). https://www.merlinentertainments.biz/
13. Meow Wolf financials and the for-profit immersive-experience segment (CB Insights / PitchBook / Artnet News, 2024–2026). https://www.cbinsights.com/company/meow-wolf/financials
14. National Park Service, National Historic Preservation Act, National Register of Historic Places, and the 20% Historic Tax Credit. https://www.nps.gov/subjects/taxincentives/index.htm
15. Land Trust Alliance, 2020 National Land Trust Census (~1,281 land trusts; ~234,000 volunteers; 61 million acres conserved). https://landtrustalliance.org/newsroom/press-releases/61-million-acres-voluntarily-conserved-in-america-2020-national-land-trust-census-report-reveals
16. National Park Service, Concessions (Commercial Services Program). https://www.nps.gov/subjects/concessions/index.htm
17. U.S. Bureau of Economic Analysis, Outdoor Recreation Satellite Account, 2023. https://www.bea.gov/news/2024/outdoor-recreation-satellite-account-us-and-states-2023
18. Internal Revenue Service / U.S. Treasury, Conservation Easements and Syndicated Conservation Easement Transactions as Listed Transactions (Final Regulations, Oct. 8, 2024). https://www.federalregister.gov/documents/2024/10/08/2024-22963/syndicated-conservation-easement-transactions-as-listed-transactions
19. Internal Revenue Service, Unrelated Business Income Tax (UBIT) and 501(c)(3) rules. https://www.irs.gov/charities-non-profits/unrelated-business-income-tax
20. NPR / The Washington Post, IMLS Executive Order 14238, grant terminations, and December 2025 reinstatement (2025). https://www.npr.org/2025/12/04/nx-s1-5633347/libraries-museums-federal-funding-imls-trump-cuts
21. Smithsonian Institution, About the Smithsonian (federal trust instrumentality; budget above $1 billion). https://www.si.edu/about/
22. U.S. Census Bureau, County Business Patterns and Economic Census — coverage and methodology (government establishments and non-employers excluded). https://www.census.gov/programs-surveys/economic-census/year/2022/guidance/understanding-naics.html