The course to a Klamath Basin water agreement was a rocky one.

A documentary delving into decades-long water controversy in the Klamath Basin is being screened tonight in Portland during a special invitation-only event.

The Oregon Historical Society is hosting a special screening of the 90-minute documentary “A River Between Us” for former Govs. John Kitzhaber and Ted Kulongoski. Both appeared in the film, as did former California Gov. Arnold Schwarzenegger, but he will not be attending.

Members of the Oregon State Legislature, representatives of Basin tribes, Southern Oregon farmers, businesspeople and activists who participated or appeared in the film are invited to attend.

On-project farmer Steve Kandra, Klamath Water Users Association Executive Director Greg Addington, and Upper Basin Ranchers Becky Hyde and Matt Walters are featured in the film’s trailer. Lower Basin tribes, conservationists and other stakeholders also are featured.

“A River Between Us” is the brainchild of former Oregon Senator Jason Atkinson, who represented Jackson and Josephine counties during his tenure in the early 2000s. Atkinson and co-producer Jeff Martin also will attend the screening.

For the film, Atkinson and Martin spent two years completing 70 interviews.

According to a news release, the film captures the end of nearly a century of water wars, in which farmers, tribes, local and regional industry, and environmental activists have been pitted against each other for rights to water in the Klamath River Basin.