Brad Speidell, who along with family members built and run cannabis retailer The Green Solution, has listed his Observatory Park mansion for $5 million. Speidell is chief sales officer at TGS Global, the Denver-based parent company of The Green Solution medical and recreational marijuana retailers. He purchased the home on the 2400 block of South Adams Street appropriately enough on April 20, 2021, for $3.8 million, according to property records.