some grizzlies were out in the meadow and my dad stopped the van to get out and take pictures. He walked about halfway from the van to the bears.
Some ranger came up to him and asked "How long would it take you to run back to your vehicle?" My dad said "about 20 seconds". Ranger: "the bears can be there in 10." and ranger just walked away. my dad took the hint and got back in the van.