Andrew Kearns / National Park Service via The New York TimesPetrified Forest National Park in northeastern Arizona.

Last year there were a record number of visitors to the National Park Service’s more than 400 parks, monuments, battlefields, seashores and other sites. Those numbers are expected to increase as the agency approaches its centennial on Aug. 25, 2016.

The wealth of visitors is great but spreading it around can be a challenge, said Kathy Kupper, a spokeswoman for the park service in Washington.

“The iconic parks are always jammed, but there is incredible wildlife in Theodore Roosevelt, too,” she said, referring to the national park in North Dakota. “It’s just not on people’s radar.”

The same is true for the agency’s historic and cultural sites, she said.

“There’s a lot of focus right now on finding gaps in our collective history and culture. Not to take anything away from the classics, but the parks are more than wilderness.”

Park visitors are likely to see a nominal increase in entry fees, the upside of which is enhanced programming and visitors’ centers, lodging expansion and trail restoration, especially for bike use.

Below are highlights by state.

Arizona

Petrified Forest National Park is now mapping self-guided hikes to its more off-the-beaten-path destinations leading to petroglyphs, Triassic-era conifers or fossil beds in the Red Basin, the park’s newest land acquisition.

California

Tioga Road, Yosemite’s main corridor, has undergone major repairs to fix pavement and signs, add parking and improve bathrooms. In March, the park reintroduced a herd of endangered Sierra Nevada bighorn sheep to Cathedral Range.

Colorado

Wetherill Mesa, known as the quieter side of Mesa Verde National Park, will have an extended season this year (through mid-October), giving cyclists ample time to enjoy new access to the park’s 6-mile Long House Loop as well as backcountry routes on the park’s most popular hike.

District of Columbia

The Rock Creek Park GPS-enabled mobile app is in the final stages of development, according to the Rock Creek Conservancy, and is likely to be ready in time to assist with the park’s 125th anniversary in September.

Hawaii

Hawaii Volcanoes National Park is helping campers take a load off at its Namakanipaio campground with a tent and supply rental option. Hawaii Volcanoes Lodge Company will set up and break down a campsite for two, including a tent, a mattress, linens, a cooler, a lantern and chairs.

Illinois

In February, President Barack Obama gave Chicago its first national park site when he designated the Pullman Historic District a national monument. The first planned industrial community in the United States and the birthplace of the first African-American labor union, the remaining Pullman Palace Car Company buildings are “an evocative testament to the evolution of American industry,” the presidential proclamation stated.

Louisiana

The New Orleans Jazz National Historical Park is now offering weekly Jazz Pilates classes taught by Stephanie Jordan, a jazz vocalist and Pilates instructor who integrates the traditional practice with dance and the music of John Coltrane, Kidd Jordan and others.

Maine

Acadia National Park is to begin managing a new campground on Maine’s Schoodic Peninsula this fall. The site will offer almost 100 RV and tent sites, as well as new hiking and biking trails connecting to Gouldsboro Village and existing park trails leading to the peninsula’s tip. Look to book a spot beginning in September.

New Hampshire

Once home to the sculptor Augustus Saint-Gaudens, Saint-Gaudens National Historic Site, New Hampshire’s only national park, has one of the oldest artist-in-residence programs in the system and a significant body of work from which to choose pieces for its retrospective exhibition opening in September.

South Dakota

The new visitor center at the Minuteman Missile National Historic Site sounds more like a museum than an information desk. Interactive exhibits and films there cover the intercontinental ballistic missile system and its role in the Cold War. New programming will begin at the facility in a lead-up to the grand opening on Sept. 26.

Tennessee

Chimney Tops, the most heavily trod trail in Great Smoky Mountains National Park, has reopened after major maintenance to help ensure its long-term sustainability and safety.

Utah

Moab Giants, a new dinosaur exploration park, should open just in time to feed on the fans of “Jurassic World” this summer. The 40-acre grounds north of Moab will focus on the tracks of area dinosaurs from the early Jurassic through the early Cretaceous periods.

Virginia

Shenandoah National Park is expanding its programming for children. In addition to redesigning its Junior Ranger program, the park is to designate Blackrock Trail an official Kids in Parks Track Trail.

Wyoming

Three of five lodges planned for Yellowstone’s Canyon Lodge and Cabins complex should be ready in August. The $70 million project was set in motion to replace more than 300 outdated cabins and to increase sustainability practices at the park’s largest accommodations.