| St Mary Land & Expl Co | 102052 | Denver | 1 | 1 |
| St Oil Company | 102053 | Denver | 3 | 1 |
| St Oil Company (Navajo Wells) | 102054 | Denver | 0 | 0 |
| St Thomas Oil Co | 102056 | — | 1 | 1 |
| Stacey, Paul S & Assoc | 102057 | — | 1 | 1 |
| Stadia Oil & Uranium | 102058 | — | 1 | 1 |
| Stallworth, Robert B | 102059 | — | 1 | 1 |
| Standard Energy Corp | 102060 | Salt Lake City | 5 | 2 |
| Standard Oil Co of Calif | 102062 | — | 10 | 4 |
| Standard Oil Production Co | 102063 | Houston | 0 | 0 |
| Standlee, J A | 102064 | — | 1 | 1 |
| Stanford Petroleum | 102065 | — | 1 | 1 |
| Stanolind Oil & Gas Co | 102066 | — | 5 | 4 |
| Star Acquisition III LLC | 102067 | Englewood | 0 | 0 |
| Star Crescent Oil Co | 102068 | — | 2 | 1 |
| Star Oil Operating Company, LLCActive | 105521 | Laramie | 136 | 1 |
| Starfighter Petroleum Inc | 102069 | Litchfield Park | 0 | 0 |
| Starlight Oil & Gas LLC | 102070 | Greenwood Village | 1 | 1 |
| Starner Drilling | 102071 | — | 2 | 1 |
| Stava Oil Company | 102072 | — | 1 | 1 |
| Stellar Oil Co | 102073 | — | 1 | 1 |
| Stephens Energy Company LLC | 102074 | Fort Smith | 1 | 1 |
| Sterling Energy Corp | 102075 | Denver | 1 | 1 |
| Stevenson, Albert | 102076 | — | 1 | 1 |
| Stewart & Stevenson MVO | 102077 | Denver | 0 | 0 |
| Stewart Petroleum Corp | 102078 | Greenwood Village | 14 | 2 |
| Stewart-Six Et Al | 102079 | — | 2 | 1 |
| Stierwalt Et Al | 102080 | — | 1 | 1 |
| Stoddard Drilling Company | 102081 | — | 8 | 1 |
| Stone Energy Corporation | 102082 | Lafayette | 1 | 1 |
| Stone Energy LLC | 102083 | Lafayette | 17 | 1 |
| Stone, D J | 102084 | Palo Alto | 4 | 1 |
| Stonegate Resources LLC | 102085 | Park City | 0 | 0 |
| Strategic Energy Exploration Inc | 102086 | Vernal | 0 | 0 |
| Strategic Oil and Gas, LLC | 105806 | Sheridan | 0 | 0 |
| Stripper Operating Inc | 102087 | Roosevelt | 0 | 0 |
| Strobel, R S | 102088 | — | 1 | 1 |
| Stronex Resources, LLCActive | 102089 | Pleasant Grove | 3 | 1 |
| Stroock, Rogers & Dymond | 102090 | — | 0 | 0 |
| Stubbs, Glade | 102091 | — | 5 | 1 |
| Subsurface Resources Inc | 102092 | Logan | 1 | 1 |
| Sue-Ann Operating LC | 102093 | Vernal | 2 | 1 |
| Suma Oil & Gas LLC | 102094 | Omak | 2 | 1 |
| Summit Operating, LLCActive | 102095 | Orem | 33 | 3 |
| Sun Explor & Production Co | 102096 | Oklahoma City | 4 | 2 |
| Sun Gas Company | 102097 | Dallas | 0 | 0 |
| Sun Internatl/Mack Well Se | 102098 | — | 2 | 1 |
| Sun Oil Company | 102099 | — | 18 | 8 |
| Sundial Exploration Co | 102100 | — | 1 | 1 |
| Sunfield Energy Company | 102101 | Houston | 3 | 1 |
| Sunray Dx Oil Co | 102102 | — | 19 | 4 |
| Sunstone Energy Co | 102103 | Tulsa | 0 | 0 |
| Superior Oil Company | 102104 | Dallas | 111 | 7 |
| Supreme Western Petroleum | 102105 | Denver | 0 | 0 |
| Supreme X Oil Company | 102106 | — | 3 | 1 |
| Supron Energy Corporation | 102107 | — | 5 | 1 |
| Sutherland Oil Company | 102108 | Pagosa Springs | 7 | 1 |
| Sutherland Oil Company | 102109 | Mexican Hat | 0 | 0 |
| Swank, G W | 102110 | — | 1 | 1 |
| Swartsbaugh & McMillian | 102111 | — | 2 | 1 |
| Swenco-Western | 102112 | Denver | 1 | 1 |
| Swepi LP | 102113 | Houston | 1 | 1 |
| Swepi/Western Division | 102114 | Houston | 7 | 3 |
| Swevco-Sabw LLC | 102115 | Houston | 0 | 0 |
| Syndicate Oil & Mining Co | 102116 | — | 5 | 3 |
| Synergy Operating, LLCActive | 102117 | Farmington | 4 | 1 |
| T-Rex Corp | 102118 | Oklahoma City | 1 | 1 |
| T.E.S. Water Injection, LLCActive | 102119 | Cortez | 1 | 1 |
| Taiga Energy Inc | 102120 | — | 0 | 0 |
| Tall Dune Resources, LLCActive | 105118 | Boerne | 19 | 1 |
| Tamarack Energy Inc | 102121 | Midland | 0 | 0 |
| Tatex Energy | 102122 | Oklahoma City | 1 | 1 |
| Taylor & Taylor | 102123 | — | 2 | 1 |
| Taylor Brothers Oil Co | 102124 | — | 1 | 1 |
| Taylor, D Et Al | 102125 | — | 1 | 1 |
| Taylor, R M | 102126 | — | 1 | 1 |
| TBI Exploration Inc | 102127 | Midland | 0 | 0 |
| TCC Royalty Corporation | 102128 | Centennial | 3 | 1 |
| Tcpl Resources USA LTD | 102129 | Denver | 0 | 0 |
| Teb Inc | 102130 | Toronto | 7 | 1 |
| Teck Cominco American Inc | 102131 | Spokane | 0 | 0 |
| Tejas Gas Corp | 102132 | — | 7 | 1 |
| Temex Energy Inc | 102133 | Shreveport | 0 | 0 |
| Tenneco Oil Company | 102134 | Houston | 94 | 9 |
| Tenneco Oil Company | 102135 | Denver | 0 | 0 |
| Tennessee Gas Trans Co | 102136 | — | 3 | 1 |
| Teocali Energy, LLC | 105583 | Denver | 0 | 0 |
| Teppco Crude Oil LLC | 102137 | Denver | 0 | 0 |
| Terra Resources Inc | 102138 | Casper | 5 | 3 |
| Terra Resources Inc | 102139 | Casper | 0 | 0 |
| Tesoro Logistics RockiesActive | 102140 | San Antonio | 0 | 0 |
| Tesoro Logistics, LPActive | 102141 | San Antonio | 0 | 0 |
| Tesoro Refining & Marketing | 102142 | Denver | 0 | 0 |
| Teton Energy Co Inc | 102143 | Denver | 6 | 3 |
| Tex-Am Oil Co | 102144 | — | 1 | 1 |
| Tex/Con Oil & Gas Co | 102145 | Dallas | 0 | 0 |
| Texaco E & P Inc | 102146 | Houston | 35 | 4 |
| Texaco E & P Inc | 102147 | Orangeville | 0 | 0 |
| Texaco Inc | 102148 | Farmington | 111 | 9 |
| Texaco Inc | 102149 | Rock Springs | 0 | 0 |
| Texaco Inc | 102150 | Midland | 0 | 0 |
| Texaco Producing Inc | 102151 | Rock Springs | 10 | 2 |
| Texaco Trading & Trans Co | 102152 | Denver | 0 | 0 |
| Texakoma Oil & Gas Corpora | 102153 | Dallas | 4 | 1 |
| Texakoma Operating LP | 102154 | Plano | 1 | 1 |
| Texas American Oil Corp | 102155 | Midland | 2 | 1 |
| Texas Eastern Oil Company | 102158 | Houston | 0 | 0 |
| Texas Eastern Skyline Oil | 102159 | Houston | 29 | 4 |
| Texas Eastern Trans Co | 102160 | — | 1 | 1 |
| Texas Energy Petro Corp | 102161 | Humble | 2 | 1 |
| Texas Gas Exploration Corp | 102162 | — | 2 | 2 |
| Texas Gulf Producing Co | 102163 | — | 1 | 1 |
| Texas International Petro | 102164 | Oklahoma | 2 | 2 |
| Texas Meridian Resources | 102165 | Houston | 0 | 0 |
| Texas Oil & Gas | 102166 | Denver | 4 | 2 |
| Texas Pacific Coal & Oil | 102167 | — | 2 | 2 |
| Texas Pacific Oil Co | 102168 | — | 2 | 1 |
| Texas Production Co | 102169 | — | 2 | 1 |
| Texoma Production Co | 102171 | — | 16 | 1 |
| Texota Oil Company | 102172 | — | 10 | 2 |
| TGX Corportation | 102173 | Shreveport | 0 | 0 |
| The Oregon Bank | 102176 | — | 0 | 0 |
| The Texas Company | 102177 | Ft Worth | 2 | 1 |
| Thermal Exploration | 102178 | Englewood | 0 | 0 |
| Thomas, Isabell | 102179 | — | 5 | 1 |
| Thomas, J P | 102180 | — | 2 | 1 |
| Thomasson Petroleum E&P LLC | 102181 | Denver | 0 | 0 |
| Thompson, J C | 102182 | Denver | 9 | 1 |
| Thompson, J C | 102183 | Denver | 0 | 0 |
| Three States Natural Gas | 102184 | — | 6 | 3 |
| Thriftway Company | 102185 | Farmington | 4 | 1 |
| Thunderbird Drilling Co | 102186 | — | 1 | 1 |
| Thunderbird Oil Co | 102187 | — | 4 | 1 |
| Thurston Energy Operating | 102188 | Vernal | 23 | 1 |
| Tidewater Co | 102190 | — | 10 | 5 |
| Tidewater Oil & Gas Company, LLCActive | 102189 | New York | 10 | 2 |
| Tierra Petroleum | 102191 | — | 3 | 1 |
| Tiger Energy Operating, LLCActive | 102192 | Los Angeles | 9 | 2 |
| Tiger Oil Co | 102193 | — | 12 | 5 |
| Tilton & Wilson | 102194 | — | 1 | 1 |
| Tintic Consolidated Metals, LLC | 105414 | Eureka | 0 | 0 |
| Tipperary Oil & Gas Corp | 102195 | Denver | 3 | 3 |
| Titan Energy Corp | 102196 | Thomasville | 0 | 0 |
| Titan Oil Inc | 102198 | — | 3 | 1 |
| TOC Oil, IncActive | 104531 | Denver | 8 | 1 |
| Toklan Oil & Gas Corp | 102199 | Tulsa | 0 | 0 |
| Tola Production Company | 102200 | Garland | 0 | 0 |
| Toledo Mining Co | 102201 | Irving | 10 | 4 |
| Toles & Toles Drilling | 102202 | — | 1 | 1 |
| Tom Brown Inc | 102203 | Midland | 0 | 0 |
| Tom Brown Inc | 102204 | Moab | 0 | 0 |
| Tomlinson, SID | 102205 | — | 1 | 1 |
| Toney, Anna V | 102206 | — | 1 | 1 |
| Toney, W W | 102207 | — | 7 | 1 |
| Torch Energy Corporation | 102208 | Denver | 1 | 1 |
| Tosco | 102209 | — | 1 | 1 |
| Total Minatome Corporation | 102210 | Houston | 0 | 0 |
| Total Petroleum Inc | 102211 | Houston | 2 | 1 |
| Tower Energy LLC | 102212 | Roosevelt | 0 | 0 |
| Tower Petroleum Co | 102213 | — | 1 | 1 |
| Townsen, C W & Larsen, R J | 102214 | — | 2 | 1 |
| Trans Delta Oil & Gas | 102215 | — | 1 | 1 |
| Trans-Western Petroleum | 102216 | — | 1 | 1 |
| Trans-Western Petroleum LTD Inc | 102217 | Golden | 3 | 1 |
| Transcanada Energy Mrkting | 102219 | Calgary, Alberta | 0 | 0 |
| Transco Exploration Co | 102220 | Houston | 5 | 1 |
| Transcontinental Oil Co | 102221 | — | 3 | 1 |
| Transfuel Resources Co | 102222 | Houston | 0 | 0 |
| Travis Oil Co | 102225 | Los Angeles | 2 | 1 |
| Trek Exploration Company | 102226 | Castle Rock | 0 | 0 |
| Trend Oil Co | 102227 | Petaluma | 8 | 1 |
| Trend Oil Company Operator | 102228 | Petaluma | 0 | 0 |
| Tres Oil Company | 102229 | — | 2 | 1 |
| Triage Energy Corporation | 102230 | Midland | 1 | 1 |
| Triage Energy Corporation | 102231 | Tampa | 0 | 0 |
| Triangle Development Co | 102232 | — | 2 | 1 |
| TriBar Resources, LLC | 105422 | Westlake | 47 | 6 |
| Tricentrol Resources Inc | 102233 | Englewood | 12 | 1 |
| Trigg Drilling Company Inc | 102234 | Denver | 0 | 0 |
| Trilogy Res Holding Co | 102235 | Calgary, Alberta | 0 | 0 |
| Trinity Explor & Prod Inc | 102236 | Houston | 1 | 1 |
| Trinity Petro Explor Inc | 102237 | Denver | 0 | 0 |
| Triton Oil Company | 102239 | — | 2 | 1 |
| Triumph Corporation | 102240 | — | 0 | 0 |
| True Oil Company | 102241 | — | 13 | 2 |
| True Oil, LLC | 102242 | Casper | 6 | 2 |
| Trust Lands Administration | 102243 | Salt Lake City | 0 | 0 |
| Tully, F M | 102244 | — | 1 | 1 |
| Twin Arrow Inc | 102245 | Rangely | 1 | 1 |
| Twin Arrow Inc | 102246 | Rangely | 0 | 0 |
| Twin Bridges LLC | 102247 | Denver | 0 | 0 |
| Twin Bridges Resources, LLC | 104867 | Denver | 0 | 0 |
| TXO Production Corp | 102248 | Cody | 71 | 3 |
| Txp Operating Company | 102249 | Houston | 2 | 1 |
| U Cal Petroleum G LTD | 102250 | — | 1 | 1 |
| U O & G Inc | 102251 | Wheatridge | 2 | 2 |
| U of U Research Institute | 102252 | XXXXXXXXXXXXXXX | 2 | 1 |
| U R C Corporation | 102253 | Denver | 1 | 1 |
| U S Biological Survey | 102254 | — | 1 | 1 |
| U S Operating Inc | 102256 | Dallas | 0 | 0 |