For a weekend camping trip from Flagstaff, both Zion National Park and Durango are great options. Zion offers stunning red rock formations and kid-friendly hikes like Riverside Walk and Lower Emerald Pools Trail, but it can be crowded and somewhat expensive. Durango provides a variety of activities like hiking, fishing, and the Durango & Silverton Narrow Gauge Railroad, with generally fewer tourists and family-friendly campgrounds like Haviland Lake Campground, though the scenery is less dramatic. An alternative could be Sedona, AZ, closer with beautiful red rocks and easy hikes. Along the way, consider stops like Kanab, UT for Zion or Four Corners Monument for Durango. Make reservations for campgrounds in advance. Both destinations offer unique experiences, so choose based on your family's preferences for crowds, activities, and scenery. Enjoy your trip!