Thirteen people have been charged with entering closed areas around Grassi Lakes and Highway 742 as crews continue work to reduce rockfall hazards near Canmore. Alberta Forestry and Parks says conservation officers have also issued two warnings and cautions that anyone entering the closure area could face further enforcement action. “Our number one concern is the safety of Albertans and visitors to the area,” a spokesperson for Alberta Forestry and Parks said in an email to CTV News. “We understand that this closure may be disappointing to visitors, and local visitor centre staff are available to assist with alternative trails that are open and safe to use. Enforcement action may be taken against anyone trespassing.” “Going into the closure area is not safe.” The Grassi Lakes day-use area and several hiking trails were closed after heavy rain earlier this season increased the risk of rockfall beyond the area affected by a June 10 slide along Highway 742. The province says Alberta Transportation and Economic Corridors is working to address the active rockfall risk. Weather permitting, the work is expected to be completed in mid-August. Alberta Forestry and Parks staff are closely monitoring the situation, and the trails will reopen once they are deemed safe. Forestry and Parks says staff will continue monitoring conditions and the trails will reopen only when they are considered safe. The Grassi Lakes Upper, Grassi Lakes Interpretive and Reclaimer trails remain closed. The Riders of Rohan trail remains open and accessible, although the province says it is much steeper and more difficult than the Grassi Lakes trails. Visitors are being urged to obey all closure signs and check trail advisories before travelling.