Lava entered the ocean early Tuesday morning, just two months after emerging from a vent at Kilauea Volcano and beginning a steady flow toward the sea.

It’s the first time lava has reached the ocean since August 2013.

The Hawaiian Volcano Observatory reports the 61G lava flow crossed the emergency access road in Hawai‘i Volcanoes National Park on Monday and entered the ocean at 1:12 a.m.

The county built the gravel road, cutting through old lava flows to connect Highway 130 to Chain of Craters Road, at a cost of $5.1 million when the town of Pahoa was threatened by lava in 2014. The Federal Emergency Management Agency covered 75 percent of the cost.

That flow stopped just short of reaching Highway 130.

Jessica Ferracane, a spokeswoman for the national park, estimated about 200 to 300 people hiked to the flow as it crossed the road Monday afternoon and evening. The glow from the ocean entry can be seen from the access road, and the spectacle is expected to attract more people in the coming days.

The lava began streaming toward the ocean after a May 24 eruption from the northeast and east flanks of the Puu Oo vent. The northeast eruption faded, and lava from the east vent reached the Pulama Pali on June 28.

The flow advanced about 2 miles along the coastal plain until reaching the ocean Tuesday.

Janet Babb, a spokeswoman for the volcano observatory, said it is impossible to predict how long the ocean entry will last.

The last lava flow to enter the ocean, the Peace Day flow, made its first entry in 2011 and continued — off and on and in different locations — until 2013.

Ferracane said even though people can hike to the flow on the gravel road, the trek is not for everyone and those who do should be prepared with water, sturdy shoes, appropriate clothing and flashlights if staying after dark.

“You still need to be a fit person,” she said. “It’s 10 miles round trip and there are no services.”

Observatory geologists warn visitors that there are significant hazards for people wanting to hike over lava to the area where the flow is entering the ocean.

“Venturing too close to an ocean entry exposes you to flying debris created by the explosive interaction between lava and water. Also, new land created is unstable because it is built on unconsolidated lava fragments and sand. This loose material can easily be eroded away by surf, causing the new land to become unsupported and slide into the sea. Finally, the interaction of lava with the ocean creates an acidic plume laden with fine volcanic particles that can irritate the skin, eyes and lungs.”

Ferracane said if tradewinds are blowing, the lava plume tends to blow toward the park and away from the county access area on the other side of the flow.

She encouraged those going to the area from Chain of Craters Road to check in at the Coastal Ranger Station, where information on safe lava viewing is available.