According to the National Park Service, Yellowstone National Park set a record with its busiest May ever. The park hosted 446,875 visits in May 2018, that is more than a 6 percent increase over last year, which saw 419,635 visits and surpasses May 2016, which saw 444,630 visits.

So far in 2018, the park has hosted 570,823 visits, up 3.5 percent from the same period last year. The list below shows the trend over the last five years. Year-to-date visitation in 2018 is 27 percent higher than five years ago in 2014.

Year-To-Date Recreation Visits (through May)

2018 - 570,823
2017 - 550,486
2016 - 593,755
2015 - 518,087
2014 - 415,185

YNP/Facebook.com

Yellowstone officials stress that the continued high levels of visitation in the park underscores the importance of planning a Yellowstone adventure ahead of time. Visitors should anticipate delays or limited parking at popular destinations, and check road conditions on the park’s website before they arrive.

Along with heavier crowds come increased numbers of encounters between people and animals in the park. There have been three incidents in the past week where people in YNP have reported being injured by animals.

A woman was attacked on June 3 by an elk behind the Mammoth Hot Springs Hotel. The 51 year-old, who is an employee of the hotel, was kicked multiple times by the elk's front legs, hitting her in the head, torso and back.

The second such incident involved a 53 year-old woman, who was attacked by an elk in an accidental encounter behind the same hotel on June 5.

According to park officials, the third attack occurred on June 6, when a 59-year-old woman was in a crowd of people that, at one point, got within 15-feet of a bison. The animal became agitated and charged the victim near the Fountain Paint Pot in the Lower Geyser Basin.

(The National Park Service contributed to this story)