A securement mechanism for a ladder tree stand includes jaws pivotably attachable to a platform. When open, a tree can pass between the jaws. A strap assembly attaches to the jaws. A tension can be applied to the strap assembly from the ground before climbing the tree to pivot the jaws to close around the tree. The strap assembly can be anchored to the tree so that the jaws are pulled closed against the tree. A respective end portion of the strap assembly can attach to each of the jaws between its pivot axis and free end. The strap assembly can include a pivot strap secured to the jaws and a tensioning strap connected to the tree and secured to the pivot strap to slide along its length.