CHEYENNE, Wyo. -

Ski resorts in Wyoming, Idaho, Colorado, New Mexico and Utah have been forced to delay opening for the Thanksgiving holiday weekend or have few ski runs open because unseasonably warm weather limited their ability to make man-made snow.

In Wyoming, resorts at Grand Targhee and Jackson Hole were not predicting Wednesday when they would open.

Sun Valley Resort in Idaho will only have one run open on Thursday and possibly through the weekend.

Snowpack in Colorado's mountains is at its lowest level in 30 years and the Beaver Creek resort pushed back its opening day from Wednesday to Friday.

In recent years, many Western U.S. ski resorts started opening by Thanksgiving.

Grand Targhee Resort spokesman Ken Rider says the ski area last delayed its ski season start in 1998.