Nature Conservancy. Don't Move Firewood.
Provides specific state information on their firewood regulations and recommendations (includes Canada and Mexico).
National Plant Board.
The U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Plant Protection and Quarantine Program (USDA, APHIS, PPQ) and the plant health agencies in each of the 50 states, regulate the shipment of nursery and greenhouse stock in an effort to minimize the spread of harmful insects, diseases, and other pests. The Federal & State Quarantine Summaries is designed as a reference tool for nursery stock growers, brokers, purchasers, and others involved in the buying selling, and interstate transport of nursery and greenhouse plant crops. It outlines the basic quarantine and other plant health requirements of APHIS, all 50 states, and the Commonwealth of Puerto Rico and Guam. The information presented here is designed as an aid to help users avoid costly delays, rejections of plant material shipments, and introduction of harmful pests into new areas.