This is from a DEA publication on LSD manufacture:

"LSD has been manufactured illegally since the 1960â??s. A limited number of chemists, probably less than a dozen, are believed to be manufacturing nearly all of the LSD available in the United States. Some of these manufacturers probably have been operating since the 1960â??s."

"Drug law enforcement officials have surmised that LSD chemists and top echelon traffickers form an insiderâ??s fraternity of sorts. They successfully have remained at large because there are so few of them. Their exclusivity is not surprising given that LSD synthesis is a difficult process to master. Although cooks need not be formally trained chemists, they must adhere to precise and complex production procedures. In instances where the cook is not a chemist, the production recipe most likely was passed on by personal instruction from a formally trained chemist. Further supporting the premise that most LSD manufacture is the work of a small fraternity of chemists, virtually all the LSD seized during the 1980â??s was of consistently high purity and sold in relatively uniform dosages of 20 to 80 micrograms."