The South Dakota Public Utilities Commission has extended a deadline to apply for party status in a case involving the Keystone XL crude oil pipeline planned for western South Dakota.

The PUC has extended the deadline to May 31.

Party status allows an area city, county, governmental agency, nonprofit organization or individual to cross-examine witnesses and take part in the discovery process.

Dakota Rural Action wanted the PUC to push the application deadline to June 10. The original deadline was May 11.

The pipeline would cover 313 miles across western South Dakota as part of a project to deliver Alberta tar sands crude oil to Gulf Coast terminals and refineries in Texas.

If approved, Keystone XL construction would begin in 2011.