For years, the battle of “Stoner Hill” has simmered in Denver’s Commons Park. But neighborhood activist Don Cohen says he recently took in the view at the prominent hill — a feature that has hidden areas of the riverfront park from view and sometimes made it a magnet for the homeless and drug activity — and marveled at a change.

Largely absent this year, thanks to a mix of new security measures and an increasing number of public events, have been the dozens of homeless and transient youths who laid claim to the hill for several recent summers.

Instead, Cohen said of that recent Sunday evening, local jazz musicians performed at the base of the same hill for a few hundred people who sat up on the slope. They were a mix of residents from the senior living community across the street, millennials who populate the area’s apartment buildings and families with toddlers. Plenty brought their dogs.

“It was pretty magical,” Cohen said. “And it was cool — it was the first time anybody had ever done music in the park, and on the side of the hill, there’s a natural amphitheater-type of effect.”

He hopes to see more concerts and large events in the park’s future — and fewer of the problems that dogged Commons Park beginning in 2013, when its proximity to downtown seemed to crystallize what neighborhood leaders saw as a problem that threatened to ruin Riverfront Park’s backyard.

Denver Parks and Recreation officials and Cohen’s Riverfront Park Association tried out different strategies to nudge along homeless adults and the young people, including a heavy mix of pot smokers and other drug users, who sat on the hill and surrounding areas for much of the day. And for a few years, they had little success.

Fencing went up around the hill in early 2015, ostensibly to restore the well-trod sod. But the gathering spot simply moved that summer to the park green across a walking path. And it returned to the hill that fall when the fence came down.

The last year, though, has brought noticeable change.

“Really, it came within the last 12 months,” said Cohen, the neighborhood association’s president. “When you think of where we were last year, we had eight cop cars up on the hill after a meth guy went and clocked a police officer. I sort of felt like that was the low point.”

How parks officials, police and leaders in the higher-income neighborhood went about reclaiming the park involved several tactics — some of which raised tensions with the Stoner Hill youths and drew criticism from advocates for the homeless community.

But for Cohen and some other residents, the presence of drug activity and large groups of people who occupied the hill for long stretches of the day contributed to concerns about safety, often just perceived but sometimes real.

“Now I feel safe walking in the park again,” said Leah Whitten, a resident of one of the nearby buildings. She has multiple sclerosis and rides on an electric scooter during her daily trips in the park with her hound mix, Charley.

“I used to have a lot of people coming up and saying things to me or yelling at me,” she said. “It made me uncomfortable.”

Several factors helped change the park

In the past year or so, after lobbying by the neighborhood group, the parks department installed nine security cameras, including some on live feeds that can pan and scan into previously semihidden areas of the park.

And Cohen’s association invested in private security officers as ambassadors of sorts on the plaza between the park and the Millennium Bridge — reminding skateboarders and bike riders of the rules, giving out directions to pedestrians and providing watchful eyes.

Those efforts may have made the park less appealing for the transient crowd, but Cohen and deputy parks director Scott Gilmore more heavily credit the work done by Cohen’s group to attract events to the green, including yoga and other exercise classes.

The June 4 concert by Le Pompe Jazz was put on by Swallow Hill Music, which planned the event as the first in a monthly summer series at Commons Park.

The city made some physical changes in the park and on the hill, and Cohen’s group also worked with the original park designer, Mark Johnson of Civitas, to propose about $7 million in changes that could, if funded, include a natural playground atop the hill and other changes to draw more people to the park.

Other city efforts helped, some of them controversial. Those included homeless sweeps by police up and down the South Platte River and Parks and Recreation’s six-month experiment in the late summer and fall of 2016 with a park suspensions program — a harder-edged stance that Cohen called “enormously helpful.”

Police issued suspensions that took away individuals’ access to a particular park for 90 days when officers suspected people of illegal drug activity. Nearly half of the 40 or so suspensions were issued in Commons Park.

The American Civil Liberties Union of Colorado and a local attorney successfully challenged one man’s suspension by pointing out shortcomings in the appeals process set by the city. Although the program ended in February, parks officials say city lawyers are working out details for a possible revival of the program, and the department plans to form a working group and seek community input.

Some advocates criticize the city’s tactics

The co-founder of Sox Place, a downtown drop-in youth center that has helped many in the Stoner Hill enclave over the years, sees the changes at Commons Park differently.

“Some of what happens is simply targeting a population that cannot afford legal assistance when their rights are violated,” executive director Doyle Robinson wrote in an email. “Some of this population are fighting for their lives, for survival, not always doing it the way traditional society wants them to. Each one that is in this population has stories of why they are homeless, on the streets, addicted to various drugs and lifestyles.”

He urged more understanding and outreach, with fewer actions aimed at pushing the group out of the park.

Indeed, the gathering of youths on the hill largely has dispersed, although some occasionally stop by. Others have moved up Little Raven Street to the City of Cuernavaca Park, just north of 20th Street, neighborhood residents say.

There, a typical day finds a smaller group of youths who are blamed by residents of the Flour Mill Lofts for a recent uptick in criminal activity that included a stabbing last weekend. Police and parks officials now are focusing their attention on that area, says Gilmore, the deputy director of Parks and Recreation.

He and Cohen say the purpose of the strategies in Commons Park was not to push out some people but to restore a balance.

“Uniformly, when I talk to people in our community here, they don’t look at Commons Park as a country club,” Cohen said. “They look at it as a great municipal gathering spot. … It’s just when something gets too much of anything — if a concert is too loud or if too many travelers have gathered — then, yeah, that’s a problem.”

Gilmore said one lesson of Commons Park, which opened in 2000 just as developers began breaking ground in the Central Platte Valley, was the need for more active management and organizing of events and activities.

“Once you start getting some regular positive activity in the park, it makes people want to come back into the park,” he said.

Swallow Hill’s Jazz event was one measure of that success. The next concert is set for 6 p.m. July 9, with a performance by Brian Nelson’s electronic reggae act, Red Ninja, and food trucks.

Hanna Ackerman, Swallow Hill’s associate concert director, says she has high hopes for the series after the June concert seemingly took off organically, drawing a healthy crowd.

“It was people passing by and people who live in the apartment buildings,” she said. “I was really taken aback by how much the little micro-community wanted something like this.”