"It's kind of like a holiday," said Steve Brown, 20, from Coatesville, participating in his first-ever opening day.
Brown's friend Danny Glass, 18, could barely sleep the night before.
"Adrenaline is what kept me up," Glass said, noting that he's been fishing for years. "I like the excitement of feeling the bite."
The Pennsylvania Fish and Boat Commission issues about 850,000 fishing licenses per year, according to agency spokesman Rick Levis, and nearly 17 percent are issued in the Philadelphia region.
Before the season begins, Levis said, dozens of area streams are stocked with trout from hatcheries, including Chester County's Brandywine Creek, Neshaminy Creek in Bucks County, and Wissahickon Creek in Northwest Philadelphia.
Throughout the year, Levis said, more than three million trout are released into streams across the state.
And on opening day, anglers seek out those that they know will have a plentiful supply.
"This is where they stock, so you've got to come here first day," Glass said as he urged the worm on his hook to attract a trout.
Glass caught a fish on his first cast of the day, and many other fishers also seemed to have early success.
Fishers can catch and release as many fish as they want but are allowed to take home only five per day.
In most areas of the state, fishing isn't permitted until April 12, and New Jersey's season opens Friday.
But 18 counties in Southeastern Pennyslvania, including the entire Philadelphia region, were allowed to start Saturday, which Levis said is standard practice because the weather is typically warmer there than in many northern counties.
The regular trout season in Pennsylvania lasts until Sept. 1.
While Saturday morning's temperature wasn't exactly tropical - and rain began drizzling down later in the morning - many fishers in Coatesville said they were thrilled to get back to the water after months of punishing cold.
"After this winter we had, you can understand, whether you catch anything is a bonus," said Bob Barry, 67, from West Chester. "It's just great to be out."
Woodrow Bensinger, 23, from Honeybrook, was so excited, he camped overnight beneath the bridge on Cedar Knoll Road with his nephew and some friends.
One of them, Angelo Phillips, joined Bensinger about 4:30 a.m.
Fishing, Phillips said, is "in my blood," noting that his grandparents owned a tackle shop and his uncle made fishing rods.
But not everyone on the creek felt a need to be that dedicated.
Tapan Mukherji, 61, from New Delhi, India, stood on a rock while his son Tayush, 32, from Ephrata, did the fishing.
About 9:30 a.m., Tayush said he wasn't sure how much longer he'd stay at it.
The trout "stop biting after a while," Tayush said. "They realize, 'Hey, my friends are missing.' "
But with that, Tayush baited his hook again and let fly.