With ice on Dillon Reservoir having completely formed between Dec. 17 and 18 — a few days ahead of schedule — the Summit County Sheriff’s Office in a news release shared ice safety tips to practice this winter.

The average date that the reservoir ices over holds steady on Dec. 25 for the past 40 years, the Sheriff’s Office said.

On Dec. 18, a welfare check was called in about two ice skaters on Dillon Reservoir — with the reporting party concerned because they could hear ice cracking, the release states. A drone with a speaker was deployed and the ice skaters were alerted to the potential dangers.

Many variables can cause ice to be unsafe. It can be thick in some spots and thin in others and clear ice is capable of holding more weight than cloudy ice, the Sheriff’s Office said. There should be a minimum of 4 inches of good, clear ice before walking on a lake and at least 6 or more inches before taking a snowmobile or ATV on the ice.

Those planning to head out on the ice should also be aware of any regulations. For Dillon Reservoir, regulations prohibit snowmobiling, according to the Sheriff’s Office. Ice-goers should also have a self-rescue plan and proper equipment, such as ice picks to rescue yourself and rope to rescue others.

The Sheriff’s Office recommends traveling with a buddy and remaining spaced out on the ice. Beware of ice covered with snow that can hide cracked or weak ice or even open water, the release states.

Daily changes in temperature cause ice to expand and contract, creating cracks and possible pressure ridges, which can affect ice strength, according to the Sheriff’s Office. Extreme caution should be used when approaching pressure ridges and ice may be unstable up to 20 feet from the ridge itself.

Stay away from cracks, pressure ridges and slushy or darker areas that signify thinner ice. If you find yourself falling through the ice, remain calm, control your breathing and get your arms over the top of the ice back in the direction you came from, the Sheriff’s Office said. Kick or pull yourself horizontally onto the surface ice and don’t attempt to stand up. In the case of an emergency, call 911.