KEYSTONE, Colo. — Highway 6 reopened around 9:15 a.m. near Arapahoe Basin Saturday after nearly three days of being closed.

Staff at the ski resort popped on Twitter in the early morning hours to announce the reopening and roads nearby deteriorated into gridlock as locals and visitors lined up for a weekend on the slopes.

A-Basin stayed closed on Friday to work at reducing the avalanche danger nearby. During the morning hours, crews focused their efforts on The Professor and said after several large shots, there was minimal slide activity, according to a blog post from Alan Henceworth, the Chief Operating Officer of A-Basin.

Crews moved on to the Widowmaker to perform similar work when another large slide occurred.

"The last big shot of the day triggered a large slide on the Widowmaker, depositing a significant amount of snow and timber on Highway 6," Henceworth said in the blog post. 

Additional debris from the Widowmaker still needed to be cleared off the highway near A-Basin Saturday morning, ski resort staff said. Two snowcats were sent to assist the Colorado Department of Transportation and would hopefully be done by 11:15 a.m.

A-Basin has not been open since Wednesday due to avalanche danger. As of Friday afternoon, U.S. 6 over Loveland Pass remained closed, according to a Tweet from CDOT. It reopened Saturday morning.

The last time the ski area had to shut down was in January 2017 when an avalanche slid across Highway 6 just west of the ski area, a spokesperson for A-Basin said.

Two natural avalanches occurred early Thursday morning along Interstate 70. The first was reported just after 1 a.m. at mile marker 186 on I-70 and covered the highway with snow. It resulted in a full closure of the highway between Frisco and Copper Mountain.

RELATED: 2 avalanches expected to keep I-70 closed for hours between Frisco and Vail

A second avalanche hit around 5 a.m. near the Conoco in Copper Mountain, according to a Facebook post from Summit Fire and EMS. It ruptured a natural gas line and prompted Copper Mountain to say it would open late.

Avalanche danger was reduced to high on Friday. In a Facebook post Thursday morning, the Colorado Avalanche Information Center said four backcountry zones had gone to "extreme" (5 of 5) Avalanche Danger for the first time since the 10-zone forecast format began 12 years ago.

The last time an Extreme Avalanche Danger warning was issued was on Jan. 11, 2017, according to the CAIC.

The decision to elevate to "extreme" is subjective and decided on by the forecasters, but generally, when avalanche danger is extreme, it means the probability of avalanche is almost "certain" and the size would be "historic", according to the CAIC.

RELATED: Disney slide: Avalanche mitigation causes snow to pile onto highway for first time since 1957

As of 6:30 Saturday morning, CAIC issued an Avalanche Warning for the Front Range, Vail and Summit County, Sawatch, Aspen, Gunnison, Grand Mesa and North San Juan zones.

CAIC blamed the heavy Friday snowfall and harsh Saturday winds for creating such dangerous avalanche conditions.

SUGGESTED VIDEOS | Local stories from 9NEWS