If you're planning to visit Yellowstone National Park expect heavier than usual traffic in the days before and after the solar eclipse on August 21.

Monday, the moon will pass between the sun and earth, blocking a part of the sun – a partial eclipse – throughout the park. Yellowstone is not in the path of totality, although it is expected to be over 90%.

Yellowstone National Park is saying that roads and facilities may be overwhelmed by this large influx of visitors who are here to see the eclipse. Yellowstone does not recommend traveling in and out of the South Entrance on August 21. That entrance borders Grand Teton National Park and the center-line of the solar eclipse will pass over that park, placing it in the path of totality. August 21 is anticipated to be the busiest day in the history of Grand Teton National Park.

For up-to-date road conditions online and by phone call (307) 344-2117. Park officials are telling prospective visitors to expect to not have cell phone service, even in areas where it is normally available.

In Yellowstone, the partial eclipse will occur between 10:15 a.m. and 1 p.m. The eclipse will “peak” around 11:36 a.m. for a little over two minutes.

Please make sure if you are planning to view the eclipse to bring appropriate eclipse viewing glasses (available in park lodges, general stores, and bookstores) and solar filters for cameras, binoculars, or telescopes.