Rum-runners used the Everglades as a hiding spot during Prohibition; it was so vast there were never enough law enforcement officers to patrol it.[122] The arrival of the railroad, and the discovery that adding trace elements like copper was the remedy for crops sprouting and dying quickly, soon created a population boom. New towns such as Moore Haven, Clewiston, and Belle Glade sprouted like the crops.[5] Sugarcane became the primary crop grown in South Florida. Miami experienced a second real estate boom that earned a developer in Coral Gables $150 million. Undeveloped land north of Miami sold for $30,600 an acre.[123] In 1925, Miami newspapers published editions weighing over 7 pounds (3.2 kg), most of it in real estate advertising.[124] Waterfront property was the most highly valued. Mangrove trees were cut down and replaced with palm trees to improve the view. Acres of South Florida slash pine were cleared. Some of the pine was for lumber, but most of the pine forests in Dade County were cleared for development.[61]