HYRUM, Cache County — Drilling as part of a geotechnical exploration at Hyrum Dam began Wednesday, forcing the closure of Mount Sterling Road along the crest of the dam.

The work is expected to last 10 days and involves reclamation drill crews and geologists collecting soil and bedrock data that will be used to determine to necessity of any modifications that may be made to the dam and its spillway.

Located on the Little Bear River 10 miles from Logan, the dam and reservoir were built in 1934-35. Traffic lights will reroute traffic during the road closure period.

— Amy Joi O'Donoghue