HAMILTON, Mont. -

There's a call out to shutterbugs who take pictures in Big Sky Country, including Yellowstone and Glacier Waterton National Parks, and the Bitterroot Selway Wilderness Area.

It's time for the 21st Annual Ernst Peterson Photograph Montana contest. It honors one of Montana's legendary photographers, the late Ernst Peterson.

The Hamilton native's massive array of work found its way to Saturday Evening Post, Field and Stream and National Geographic.

Through his pictures, Peterson recorded Montana history.

Photographers may submit entries to the Ravalli County Museum in Hamilton.

"It has to be a Montana image," said museum director, Tamar Stanley. "It showcases what Ernst might have seen when he was out in the field, taking pictures or doing portraits of people."

The deadline entry is April 23. The exhibit opens May 1st. Contest judging will be May 15.

The museum houses the entire Ernst Peterson collection. That's more than 20,000 images through 40 years of work.

For entry information, visit www.brvhsmuseum.org.