One of O'ahu's most visited landmarks will soon get a multimillion-dollar makeover that includes safety improvements to mitigate the risk of rockfalls in and around the crater.

Last month, Gov. Linda Lingle released $700,000 for improvements to Diamond Head State Monument, which sees about 2,100 visitors a day.

The money is in addition to $4.4 million appropriated by lawmakers this year for improvements to the trail and park area.

Work is to start by the end of this year and could last several years.

"This is the first of that kind of money for Diamond Head," said Dan Quinn, state parks administrator, who called the funding "substantial."

"I think lawmakers have become aware of our needs to keep up with resources, particularly to those parks as heavily visited as Diamond Head," he added.

The improvements will include stabilizing the rock face above the access tunnel and other safety work throughout the state park and along Diamond Head Road.

The money follows a rockfall in May that injured a woman picnicking at the base of the cliff near the Diamond Head lighthouse. She suffered head and back injuries.

Earth Tech Inc., an environmental geotechnical firm, will assess rockfall hazards in and around the park.

Other areas to be assessed include the exterior rock faces adjacent to Poka Place and along Diamond Head Road.

The $4.4 million will help improve the historic 0.8-mile summit trail, including reinforcing the dirt path with a soil-cement surface and stabilizing areas affected by erosion.

"These funds are really needed," said Sen. Les Ihara, D-9th (Kapahulu, Kaimuki, Palolo), who supported the appropriations. "They're needed to provide safety and support the increased capacity for the trail to the summit."

The plan may include adding a one-way loop at the summit to route people back down the trail without creating gridlock in the bunker area and on the spiral staircase.

That's one improvement Diane Forte and Jim Maggio, of Long Island, N.Y., would like to see implemented.

As they descended the summit yesterday morning, the couple was stuck in a backup of hikers heading up the spiral staircase near the top of the trail.

"There were a lot of people there," said Forte, a 48-year-old accountant visiting Hawai'i for the first time. "We had to wait for everyone before we could get down."

Quinn said these improvements are important for the popular state park, which generates about a fourth of the annual $2.5 million that goes into the state parks special funds.

State parks bring in revenue from fees, concessions and permits.

Diamond Head State Monument is the only state park that collects an entry fee. It costs $1 per hiker or $5 per vehicle to enter the park.

"This has become a must-stop for people who visit the island," Quinn said. "It's quite popular, and you can see what's happened with the trail surface. So in addition to (improving) the trail, we have to make sure we address any safety problems."

Steve Kriner, 58, of Sacramento, Calif., has hiked to the summit of Diamond Head at least 10 times, enjoying the sweeping views of O'ahu's south shore from the top.

He has noticed a few changes since the last time he visited the crater about three years ago.

There are lights in the tunnel now and a lunch wagon parked at the trailhead.

Still, he sees other ways the state can improve the park, such as selling bottled water.

Landmark, one of O'ahu's top tourist draws, will be made safer, both inside and outside crater

Reach Catherine E. Toth at ctoth@honoluluadvertiser.com.