MINNEAPOLIS — All campsites at Minnesota state parks soon can be reserved, a significant change for a system that used to hold back up to a third of campsites for walk-up visitors.

The Department of Natural Resources announced the change Friday as one of a handful of moves that agency officials said were aimed at improving customer service. The agency received positive feedback when the change was tested in several state parks in the past two years, they said.

Minnesota’s 75 state parks draw thousands of visitors each year, with savvy users taking advantage of a reservation system that allows bookings up to a year in advance. Campsite bookings have risen 13 percent in the past three years.

The competition means it can be difficult to land a spot in the most popular parks, and the DNR move effectively increases the inventory of bookable campsites. That means more convenience and certainty for park users, DNR officials said.

Commissioner Tom Landwehr related a story of taking his family on a camping trip years ago, only to be turned away at Gooseberry Falls and Split Rock parks because they were full before he “got lucky” at Tettegouche State Park.

“It’s an experience that troubles a lot of people,” Landwehr said. “How will I know if a campsite will be available? We have recognized for a long time that is a challenge.”

Asked whether the change means the end of spontaneous camping at the most popular parks, DNR officials said there never was much chance of that anyway. They said non-reservable sites at popular parks were typically gone by midweek anyway, thanks to those who extended a weekend reservation or arrived midweek.

“Most of the time, the so-called good campsites were already full by Wednesday or Thursday,” Erika Rivers. “We believe this provides more opportunity for more equity.”

DNR officials said other states are moving in the same direction. North Dakota is making the change this year for all its sites, Wisconsin is piloting the idea and South Dakota has done it for years, they said.

For the spontaneous campers, the DNR is also adding same-day reservation capability. The old system cut off reservations at midnight the night before arrival. Now, campers can check availability online and book an available site immediately, rather than having to chance it under the old first-come, first-served system for nonreservable sites.

The DNR said it is also updating the registration process so that park visitors don’t have to stand in line for a staff member to register. They’ll be able to register online or via park kiosks. Signs, maps and publications are also being redesigned to be easier to use, the DNR said.

The same-day reservation capability is to be phased in over several months, beginning first in southern parks before moving north.

The changes come as the DNR marks the 125th anniversary of the state park and trail system.