The 47 largest critical infrastructure operators in Oklahoma (2026 list)

#	Company	Industry	Headquarters	Employees	Founded
1	Williams williams.com Provides transport, storage, and delivery solutions for clean energy, operating critical infrastructure to support a low-carbon energy future.	Oil and Gas	🇺🇸 Tulsa	6,995	1908
2	BOK Financial bokfinancial.com Regional financial services company offering commercial and consumer banking, investment management, brokerage, mortgage, trust, insurance, and electronic funds transfer services.	Financial Services	🇺🇸 Tulsa	6,871	1910
3	INTEGRIS Health integrishealth.org Largest Oklahoma-owned health system offering hospitals, clinics, rehabilitation, mental health, fitness, home health, and urgent care services statewide.	Hospitals and Health Care	🇺🇸 Oklahoma City	6,623	1994
4	ONEOK oneok.com Leading midstream operator provides gathering, processing, fractionation, transportation, storage, and marine export services for natural gas, NGLs, refined products, and crude oil.	Oil and Gas	🇺🇸 Tulsa	6,516	1906
5	Saint Francis Health System saintfrancis.com Integrated health system in Tulsa offering extensive healthcare services through multiple hospitals, clinics, and specialized care centers across Oklahoma.	Hospitals and Health Care	🇺🇸 Tulsa	4,699	1960
6	OU Health ouhealth.com Comprehensive academic health system in Oklahoma with hospitals, clinics, and specialty care, including the state's only freestanding children's hospital and cancer center	Hospitals and Health Care	🇺🇸 Oklahoma City	3,571	n/a
7	Chesapeake Energy chk.com An Oklahoma City-based oil and gas company focused on responsibly developing leading positions in top US plays and aiming for net zero GHG emissions by 2035	Oil and Gas	🇺🇸 Oklahoma City	2,567	1989
8	ONE Gas jobs.onegas.com A natural gas distribution company serving over 22 million customers in Kansas, Oklahoma, and Texas, with a focus on creating a respectful online community	Utilities	🇺🇸 Tulsa	2,413	2014
9	Cherokee Nation cherokee.org Sovereign tribal government with a strong focus on preserving Cherokee culture, language, and values, while also offering diverse career opportunities	Government Administration	🇺🇸 Tahlequah	2,352	n/a
10	Bank of Oklahoma bankofoklahoma.com A community-focused bank with the resources of a regional leader, offering commercial and consumer banking, investment services, and mortgage origination	Financial Services	🇺🇸 Tulsa	2,241	n/a
11	First United Bank firstunitedbank.com An innovative community bank offering a range of financial services for consumers and businesses in the Southwest, focusing on wellness and personal development	Financial Services	🇺🇸 Durant	2,009	n/a
12	City of Tulsa cityoftulsa.org Providing municipal governance, economic development, public education support, and transportation infrastructure management for a diverse industrial community through cultural preservation and resource administration.	Government Relations Services	🇺🇸 Tulsa	1,983	1898
13	OGE Energy Corp.oge.com Serving over 910,000 customers in Oklahoma and Arkansas, providing energy with focus on safety, innovation, and community improvement.	Utilities	🇺🇸 Oklahoma City	1,892	1902
14	Norman Regional Health System normanregional.com A multi-campus health system in south central Oklahoma offering acute care, physician services, outpatient diagnostics, medical transport, and wellness services	Hospitals and Health Care	🇺🇸 Norman	1,844	1946
15	City of Oklahoma City okc.gov Provides municipal services, community information, and career opportunities for residents and employees within Oklahoma City government operations.	Government Administration	🇺🇸 Oklahoma City	1,822	n/a
16	BancFirst bancfirst.bank A $12 billion assets company with over 100 locations in 60 Oklahoma communities, offering a range of personal and commercial financial products and services	Banking	🇺🇸 Oklahoma City	1,581	n/a
17	Oklahoma State Department of Health oklahoma.gov A state department focused on protecting and improving public health by preventing disease through various health services and programs	Government Administration	🇺🇸 Oklahoma City	1,367	n/a
18	Oklahoma Heart Hospital okheart.com A physician-owned hospital in Oklahoma, designed by cardiologists to provide expert, individualized care with utmost comfort in a digital environment	Hospitals and Health Care	🇺🇸 Oklahoma City	1,354	2002
19	Oklahoma Department of Transportation oklahoma.gov The company works towards providing a safe, economical, and effective transportation network for the people, commerce, and communities of Oklahoma	Government Administration	🇺🇸 Oklahoma City	1,099	n/a
20	Comanche County Memorial Hospital ccmhhealth.com Independent, non-profit acute care facility in Southwest Oklahoma, providing award-winning care with 283 beds, 2,000 employees, 250 physicians, and 100 volunteers	Hospitals and Health Care	🇺🇸 Lawton	1,057	1948
21	Oklahoma Children's Hospital OU Health ouhealth.com Innovative children's healthcare provider at OU Health, providing advanced research and treatments through hospital and outpatient services	Hospitals and Health Care	🇺🇸 Oklahoma City	999	n/a
22	Omni Air International (OAI)oai.aero An international airline specializing in tailored passenger and government charter services, airline startup support, ACMI wet leasing, and aircraft management	Airlines and Aviation	🇺🇸 Tulsa	960	1993
23	Gateway gatewayfirst.com A leading financial institution based in Oklahoma offering banking and mortgage services to individuals and businesses with a strong national mortgage presence	Banking	🇺🇸 Tulsa	946	2019
24	Stillwater Medical Center stillwater-medical.org A 117-bed acute care hospital in north central Oklahoma offering a wide range of medical services with a focus on quality care and patient satisfaction	Hospitals and Health Care	🇺🇸 Stillwater	896	1916
25	GRAND Mental Health grandmh.com A mental health organization providing outpatient therapy, rehabilitation, case management, medication management, wraparound services, and support for vulnerable populations	Mental Health Care	🇺🇸 Tulsa	857	1977
26	SandRidge Energy sandridgeenergy.com An oil and natural gas exploration and production entity focusing on high-return projects in the US Mid-Continent and Niobrara Shale regions	Oil and Gas	🇺🇸 Oklahoma City	819	2006
27	Ascension St. John healthcare.ascension.org Faith-based healthcare organization with hospitals, clinics, and facilities providing compassionate care to all, with special focus on persons in poverty	Hospitals and Health Care	🇺🇸 Tulsa	805	1926
28	Magellan Midstream Partners magellanlp.com A publicly traded partnership transporting, storing, and distributing refined petroleum products and crude oil with a focus on safety, efficiency, and responsibility	Oil and Gas	🇺🇸 Tulsa	799	n/a
29	Grady Memorial Hospital, Oklahoma gradymem.org A full-service hospital offering diagnostic, medical, surgical, and outpatient care with a 24/7 emergency center staffed by trained physicians and nurses	Hospitals and Health Care	🇺🇸 Chickasha	654	1959
30	NGL Energy Partners LP nglenergypartners.com A vertically integrated MLP in the midstream energy sector, providing transportation, storage, blending, and marketing services for crude oil, NGLs, refined products, and water solutions	Oil and Gas	🇺🇸 Tulsa	627	n/a
31	RCB Bank rcbbank.bank Established in 1936, this bank has over $41 billion in assets, 50+ locations, and 700+ employees, prioritizing high-quality service and community involvement	Banking	🇺🇸 Claremore	596	1936
32	Our Blood Institute obi.org A large nonprofit blood center providing blood for patients at over 240 hospitals in Oklahoma, Arkansas, and Texas	Hospitals and Health Care	🇺🇸 Oklahoma City	558	1976
33	Enable Midstream Partners enablemidstream.com Gathering, processing, transportation, and storage of oil and natural gas across the United States, focusing on midstream infrastructure.	Oil and Gas	🇺🇸 Oklahoma City	535	2013
34	Grand River Dam Authority grda.com GRDA operates a diverse portfolio of electric generation assets, manages lake waters in Oklahoma, and delivers wholesale electricity to various customer classes in Northeast Oklahoma	Utilities	🇺🇸 Chouteau	436	1935
35	TTCU Federal Credit Union ttcu.com A $26 billion financial institution offering depository, lending, and financial advisory services with 22 branches in Oklahoma, serving over 150,000 members	Financial Services	🇺🇸 Tulsa	417	1934
36	FSNB fsnb.com A financial institution offering banking services, home loans, and employment opportunities with a focus on equality and customer satisfaction	Banking	🇺🇸 Lawton	388	1946
37	National American Insurance Company naico.com Regional insurance carrier founded in 1987, providing commercial property and casualty coverage nationwide with strong financial ratings and partnerships with agents	Insurance	🇺🇸 Chandler	300	1987
38	ACCESS MIDSTREAM PARTNERS L.P williams.com A North American energy infrastructure company and natural gas processor leading in the industry	Oil and Gas	🇺🇸 Oklahoma City	176	n/a
39	Rose Rock Midstream semgroupcorp.com Specializing in crude oil gathering, transportation, storage, and marketing, this company operates in top resource plays in North America	Oil and Gas	🇺🇸 Tulsa	153	n/a
40	Trust Company of Oklahoma trustok.com An independent trust company offering asset management, financial advice, retirement planning, and wealth management services for individuals, families, and organizations	Financial Services	🇺🇸 Tulsa	97	1981
41	Citizens Bank of Edmond mycitizens.bank A community-focused bank in Edmond, Oklahoma with a unique ownership structure, offering co-working space and hosting local events to support small businesses	Banking	🇺🇸 Edmond	84	1901
42	AVB Bank avb.bank Established in 1905, this bank has four locations in Broken Arrow and Tulsa, known for its community-focused approach to banking	Banking	🇺🇸 Broken Arrow	72	n/a
43	First Bank of Owasso firstbank.net This company provides financial services and expertise with a focus on responsiveness and honoring God, aiming to contribute to building the Kingdom	Banking	🇺🇸 Owasso	53	1962
44	First National Bank of Oklahoma fnbok.bank Established in 1917, we are a community-focused bank dedicated to helping customers grow and prosper with honesty, integrity, and exceptional service	Banking	🇺🇸 Oklahoma City	47	1917
45	First National Bank And Trust Company Of Ardmore 1nb.com The company offers high quality financial products and personalized customer service with a competitive edge	Banking	🇺🇸 Ardmore	22	1889
46	Whiptail Midstream whiptailmidstream.com A full-service midstream provider in Tulsa, Oklahoma, offering gas gathering, NGL fractionation, crude and water storage, and transportation services	Oil and Gas	🇺🇸 Tulsa	16	2016
47	Skysill Power Services skysill.net The company focuses on developing a modern electrical grid that ensures safe, reliable power delivery, integrates renewable energy, and maximizes resilience	Utilities	🇺🇸 Glenpool	2	2022

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Every company on this list has a Tamtam company profile. The industry is the one the company gives on LinkedIn; categories such as SaaS or fintech are classified by Tamtam's AI from the company's website and LinkedIn page; and the headquarters city must match the company's own address. Companies are ranked by the number of employees on LinkedIn, and the list is refreshed every night. Classifications can be wrong, so treat the list as a starting point rather than an official ranking. Last updated Oct 24, 2026.

The 47 largest critical infrastructure operators in Oklahoma

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