TRAFFIC UPDATE: Traffic everywhere!
UPDATE 1:30 p.m.
Idaho State Police reports there is heavy traffic on southbound Interstate 15 south of Idaho Falls.
Traffic on I-15 at mile marker 119 is moved over to one lane with US 20 traffic coming onto I-15 in the other lane. Southbound exit 118 is shut down.
ISP reports traffic is flowing southbound at mile marker 116.
ISP reports there is a minor crash at mile marker 109 northbound. It is blocking traffic. Traffic in the area has slowed down.
ISP said traffic is moving along around mile marker 98.
ISP reports traffic on southbound I-15 is backed up from the Shelley exit to mile marker 128.
At the Blackfoot Interchange, traffic is going about 5 mph as motorists merge off US 26 to I-15.
ISP said south through Fort Hall is looking good.
ISP reports Sage Junction on I-15 is looking good and back to normal flow.
US 20 is also very congested. Traffic is backed up in the Ashton area and is at a standstill as of 12:33 p.m. ISP says to expect delays and please be patient.
There is a crash on US 20 at mile marker 311 westbound. ISP asks you proceed with caution.
West on US 20 to the INL Site is clear.
US 26 traffic eastbound is moving smoothly. Traffic at mile marker 398 going into Wyoming has stopped and is backed up about four miles around Alpine going into Wyoming.
HIghway 91 by Shelley is backed up.
SH31 has heavy traffic.
Traffic on SH32 is moving smoothly.
SH33 is backed up both ways for a few miles off I-15. Traffic north of Victor is moving slow.
Malad Summit looks good for those going south to Utah according to ISP.
UPDATE: 10 A.M.
Highway traffic is reaching a peak in eastern Idaho.
The Region 3 Incident Command reports I-15 northbound from Shelley to Idaho Falls is reporting slow moving bumper-to-bumper traffic. I-15 northbound in Pocatello at the Monte Vista overpass reached a peak of 3,200 cars per hour. The capacity of I-15 is roughly 4,000 cars per hour. Southbound traffic from Island Park is reported at a stand-still. Traffic between Idaho Falls and Rexburg was reported as fairly light and flowing smoothly. Mount Borah reported 400 vehicles parked in the area with approximately 1,000 people climbing to the peak. Teton County, Idaho is reporting hundreds of cars parked along many of the roads. In the face of it all, there have been no major accidents and all hospitals are operating normally.
ORIGINAL STORY:
There has been significant traffic north of the Town of Jackson on Highway 89 in both directions.
Teton County officials said that when the Gros Ventre Road reaches parking capacity from the highway east to Mormon Row, vehicles will be directed to drive around the Antelope Flats loop and continue on to the Teton Park Road. Teton Park Road will accomodate two-way traffic. In Jefferson County, people are filling in available spots on South Menan Butte. 
In Bonneville County, most accidents reported early Monday have been handled quickly. Other than an increase in overall traffic and visitors, there have been no significant incidents related solely to the eclipse. There are a number of cars stopped along US 26 and people walking near the highway. There are reports of heavy, bumper-to-bumper traffic on US Highway 20 south from Montana into Fremont County. The Wyoming Highway Patrol is reporting heavy traffic on Interstate 25 into Cheyenne. 
There are no reports of any specific issues on Interstate 15, except at the Highway 20 exit in Idaho Falls, where there are some delays. Traffic congestion is high along all regional highways and motorists are advised to drive slowly and not stop.
