FREMONT — One week after going into effect, a tighter curfew limiting access to Mission Peak Regional Park may have created more controversy than it resolved.

The hordes are still coming. And some hikers are angry, saying the East Bay Regional Park District is discouraging the public from getting healthy exercise in a public park.

The curfew is an effort to gain some level of control over a selfie-stoked Bay Area sensation: Making the challenging, three-mile hike up Mission Peak, where successful summiters are rewarded with the rush of accomplishment and a spectacular backdrop for their smartphone portraits.

Until Sept. 29, the entrance was open from 5 a.m. to 10 p.m. Now, it is closed from 7:30 p.m. to 6:30 a.m. Regional park managers and police say the longer curfew is a modest attempt to provide relief for neighbors from noise, litter and other problems at hours when most people sleep. Up to 3,000 people on some days make the trek, and many are unprepared for the hot, arduous ascent.

Park users have been showing up at the Stanford Avenue entrance at all hours. They wake up neighbors, urinate in their yards, block driveways and monopolize all the street parking within a half mile. Park police issued 475 curfew tickets at the park entrance from mid-July to mid-August. The penalty is a minimum of $300 per ticket.

Hikers who conk out on the summit hike call 911 to summon park police or Fremont firefighters for help, diverting them from other business. Park police and firefighters respond to about 20 calls a month from trail users, leaving them unavailable for other duties while responding.

And sadly, park users last year guided five dogs to death from sunstroke and exhaustion.

“We want people to use our parks, but we also want to be good neighbors and protect our resources,” said Bob Doyle, the regional park district general manager. “The increase in use at Mission Peak has been pretty amazing.”

The Stanford Avenue entrance with 42 parking spaces was only lightly used until a few years ago, when suddenly it got busy and then swamped thanks to people posting photos of themselves at the summit.

“It can be like a mall,” said Cassandra Recchioni, of Fremont, as she started the uphill trek with her mother, who is training to hike the Grand Canyon. “Facebook and social media has made it famous.”

Mission Peak also is popular because it’s accessible, challenging and affords panoramic views of San Francisco Bay and the region. And some feel safety in the big numbers on the trail there.

Roger Chen, a park neighbor, said he’s looking forward to the longer curfew because he’s tired of being awakened at 4 a.m. or earlier by people parking and talking in front of his home. “There’s too many people,” he said.

Park officials also are looking at options to build a much larger parking lot farther up the hill, or to limit visitors at the Stanford Avenue entrance through some form of permit and fee system.

Parking on neighborhood streets and in the small parking lot is now free, unlike at another park entrance at Ohlone College, where a $2 fee is charged.

Park user Kelly Abreu, of Fremont, said a larger parking lot with fees and parking meters on streets should be considered rather than permits that limit numbers.

Some other regular park users bristled at park restrictions they claim will limit access to a park where they can exercise and get fit.

Lawrence Edelson, of Fremont, said the new curfew will stop him from taking his regular mountain bike rides in the park when he gets off work.

“They should focus on enforcing the rules rather than depriving everyone of the opportunity to visit this park and catering to the interests of a few neighbors in big homes,” Edelson said.

Margery Madrano, of Newark, said reducing hours or limiting park visitors clashes with the park district’s mission to promote healthy exercise.

“In a time of widespread obesity, any action to discourage people from exercising is ridiculous,” said Madrano, a park user for 35 years. “It’s government’s role to provide what people need, and if that means hiring more people to enforce rules or building a bigger parking lot, they should do it.”

Madrano says barring hikes at night deprives people of the chance to see inspiring sunsets over the bay.

Mark Ragatz, the park district’s interim chief of operations, said park managers don’t want to drive away visitors but rather disperse them to other regional parks as a way to reduce the erosion, noise, parking and crowding problems.

“We have 65 regional parks,” Ragatz said, “and they are good outdoor places to go, too.”

Contact Denis Cuff at 925-943-8267. Follow him at Twitter.com/deniscuff.