DALLAS—William Alvin Moncrief Jr., a Texas wildcatter who helped build a father-son venture into an oil and gas empire over more than 70 years in the industry, has died. He was 101. A spokeswoman for Moncrief Oil confirmed his death to The Associated Press Wednesday but could not immediately provide further details. Moncrief, who went by the nickname “Tex,” was born in Arkansas in 1920 on his family’s kitchen table, according to Texas Monthly. His father, William Alvin “Monty” Moncrief, was among the early wildcatters to drill for oil in East Texas. The younger Moncrief spent his life building on that tradition, acquiring a fortune that earned him a reputation as a generous philanthropist but also attracted scrutiny from tax authorities. At the age of 10, Moncrief witnessed his father open a “gusher” oil well in Greggton, 128 miles east of Dallas. People who gathered to watch the drilling and …