Below are several Federal, State and miscellaneous links which may be of assistance and interest:
Sources for Federal Regulations/Standards:
Environmental Protection Agency
CFRs (including DOT regs)
Standard Industrial Classification (SIC) Codes
State Links & Directories
Oklahoma Department of Environmental Quality
Oklahoma Corporation Commission
The Environmental Federation of Oklahoma
Environmental Council of States
EPA Regions & State Environmental Departments
Miscellaneous
US Fish & Wildlife (coastal, refuge, wetlands)
The U.S Department of the Interior
The Environment Web Directory - Earth's Biggest Environment Search Engine