HADLEY — After being shuttered for four years amid construction delays and then opening for the past two seasons, the Mount Holyoke Summit House in J.A. Skinner State Park is closed to the public — again.

The former 19th-century hotel is now in need of fire suppression upgrades and repairs and will not open to the public until “early summer,” according to the state Department of Conservation and Recreation.

The state agency reports that it is replacing pipes within the fire suppression system, and that repairs are currently underway.

The Summit House is supposed to open weekends and holidays from Memorial Day through Labor Day, but never opened for the 2016 season. Although the interior is closed, the porch remains accessible to the public and port-a-johns have been placed on the property.

The historic Summit House is a popular destination for hikers and tourists and one of the state’s showpiece recreational venues. It commands spectacular, panoramic views of the Connecticut River Valley.

“It is disappointing,” Merle K. Buckhout, chairperson of the Mount Holyoke Range Advisory Committee, said. “The state moves, but it’s glacial. Until they get it either fixed or patched, that’s it.”

The Department of Conservation and Recreation has posted small signs around the property alerting visitors that the newly renovated building and its bathrooms are closed “due to unforeseen circumstances,” and would reopen in “late June.”

Troy Wall, a spokesman for the state agency, told the Gazette Thursday that the closing would not affect the 2016 Summit House Sunset Concert Series that is scheduled to begin July 7 and runs Thursdays through Aug. 4. The concerts are held inside the building and serve as a fundraiser for Friends of the Mount Holyoke Range, which organizes the series. The newly refurbished Summit House reopened to visitors in June 2014 after being closed for four years for renovations and structural repairs. It had been scheduled to reopen in 2012, but a combination of bid errors and various construction delays extended completion of the $1 million-plus project to 2014.

The major delays involved ripping out a newly installed glass-infused wood product called TimberSil and replacing it with a more common pressure-treated wood.

Staff Writer Dan Crowley can be reached at dcrowley@gazettenet.com.