Pyramid Peak in snow last winter, seen from the Unalaska Valley side of the trail. (Lauren Rosenthal/KUCB)

Unalaska police believe they’ve found the body of a hiker who went missing on Pyramid Peak on Sunday.

Jessica Acker, 33, apparently left Westward Seafoods for a hike near Pyramid on Sunday afternoon. She was reported missing when she didn’t return that night.

Late Monday afternoon, a search team spotted a person who appeared to have fallen down a snowy ravine. Unalaska police chief Jamie Sunderland says they believe it’s Acker, and have contacted her family.

But they weren’t able to recover the body or make a positive identification by nightfall.

"Conditions up there apparently were really horrible," Sunderland said on Monday night. "Apparently visibility was limited to about 10 feet, [with] a lot of wet, blowing snow."

He says the team will go back Tuesday morning to try again.

Acker was working as a fisheries observer with Alaskan Observers. Sunderland says she appears to have hiked around the far side of Pyramid, where there’s no cell service and even radio reception is patchy. The peak is 2,300 ft. tall, with miles of popular but sometimes treacherous hiking trails.

"Early on, the searching was a little more toward Westward, that side of Pyramid, but some folks had seen some tracks the day before out farther, beyond the gates out there," Sunderland says. "So we shifted our search over there in the afternoon and, of course, the body was discovered quite a ways from there still."

Sunderland says it’s not an easy trek -- but he and Acker’s family also say she had plenty of experience hiking in Alaska.

Monday's search lasted at least 12 hours and involved about a dozen public safety and Coast Guard officials and civilian volunteers, as well as a Coast Guard helicopter.

This is a developing story. Check back for updates.