Hopkinton Reservoir at Hopkinton State Park, Whitehall Reservoir, and the Hopkinton section of the Sudbury River are among the sites where the Massachusetts Division of Fisheries and Wildlife is stocking more than 529,800 brook, brown, rainbow and tiger trout this spring. Seventy-one percent of the fish average 12 inches or longer.  “We have some high-quality fish this spring,” Massachusetts Chief Fish Culturist Dr. Ken Simmons said. “We had to deal with severe drought conditions last summer and early fall.”  “The hatchery crews did an excellent job with the fish,” Simmons said. Stocking in …