Fire crews are working to stop the forward progress of a 100-acre wildfire along SH-21 near mile marker 19, southeast of Boise.The fire caused closures on the highway, and a pilot car is guiding traffic in both directions, accor ding to the Boise County Sheriffs Office. The closure was between the wildlife tunnel and High Bridge.USWFS crews are responding to the fire, along with BLM Boise District. According to a spokesperson with USWFS, the fire is estimated at 100 acres, and there is no estimated containment or control time set.The cause of the fire is under investigation.Officials say traffic is moving, but drivers should expect delays while the pilot car controls alternating flow through the area.This is a developing situation and will be updated as more information becomes available. ...read more read less