Mountain resorts generally build their reputations on snow sports. But for many mountain regions, summer is the busier season based on school vacations and the appeal of cool mountain weather when other places are sweltering.

Supplementing hiking, gondola rides and mountain biking, Vail Resorts has opened two on-mountain summer activity campuses positioned to engage more fair-weather visitors in the outdoors and balance the seasonal economies of its mountain towns.

“Our winter business has a loyal, passionate, committed following, but it’s a narrower following,” said Robert Katz, chief executive of Vail Resorts. “We have an opportunity in summer to broaden that.”

On June 28, Vail Mountain, the popular Colorado ski resort, opened Epic Discovery (vail.com), a series of summer-only attractions that bridge adventure and education. With entry via the Eagle Bahn gondola, its thrills include a canopy tour with seven zip lines that crisscross one of its famous ski bowls, Game Creek. There is also a high-ropes course and a new alpine roller coaster at 10,350 feet that relies on gravity to propel its cars.

Two short hiking trails on relatively level ground emphasize learning through play via new “story stakes,” interpretive signs that display fun facts about the strength of an eagle. According to one sign, for instance, eagles can carry food up to a third of their body weight, the equivalent of a human running up 10 flights of stairs carrying over 45 pounds of groceries.

Other installations are intended to more actively engage visitors in understanding animal abilities. For example, a bighorn sheep exhibit includes a beam that visitors can walk on to experience the balance required of these mountainside dwellers.

“These are structures that take the national park plaque to a new level,” said Hans Vollrath, senior director of summer operations for Vail Resorts, who is in charge of the signed trails. The model for the signs, he said, is “an interactive museum or zoo or kids’ museum where there are cool hands-on opportunities to learn about a subject.”

At Lake Tahoe in California, the Vail-owned Heavenly Mountain Resort (skiheavenly.com) opened similar Epic Discovery attractions last month, including a canopy tour with zip lines and aerial bridges overlooking the lake, also a gravity-based alpine coaster and interpretive learning trails.

The campus, on Adventure Peak, reached via the Heavenly Gondola, also includes a rock climbing wall, a children’s ropes course and a zip line, which opened last summer.

At both properties, all-access passes cost $89 daily, which includes most attractions, except four-wheel drive and canopy tours. Passes with a canopy tour cost $189.

The summer investments are a result of the Ski Area Recreational Opportunity Enhancement Act, passed by Congress in 2011, which allowed the Forest Service to develop guidelines for ski areas to create year-round activities in national forests.

According to the Department of Agriculture, 122 ski areas in the country operate on nearly 180,000 acres of Forest Service land. When the agency completed its guidelines in 2014, it estimated ski areas would draw 600,000 more visitors in summer, creating 600 jobs and $40 million in new spending in mountain communities as a result of expanded operations.

Vail Resorts had its plans for Vail and Heavenly approved in 2014, and as the early adopter is being viewed as a test case by other ski resorts that may be considering summer programs on their mountains beyond hiking and mountain biking, which are standard summer activities.

A third Vail Resorts property, Breckenridge Ski Resort in Colorado, plans to open more elements of Epic Discovery next summer, including a canopy tour and interpretive trails. It has an alpine coaster.

Nick Sargent, president of the nonprofit trade association SnowSports Industries America, predicted other resorts would follow the trend, noting that European mountain resorts have long offered year-round attractions.

“Everyone is trying to capitalize on the environment around the resort and use those assets 12 months of the year instead of three, four or five,” Sargent said.

Vail Resorts doesn’t lack for summer visitors — “July 4 is bigger than Christmas,” said Katz, the chief executive — but the impetus is to get some of those summer visitors from base villages up onto the slopes without asking too much in terms of effort.

Not everyone wants to climb a mountain, after all. The summer crowd is more about sightseeing.

“Epic Discovery is structured so there’s some adventure but not too much that they wouldn’t be interested in doing them,” said Vollrath, who oversees Vail’s new attractions. “A zip line might be as adventurous as they’d like to do, by and large.”