Photograph: a bearded park ranger wearing glasses and a National Park Service baseball cap speaks to someone just out of frame. Next to him, the woman park ranger from before works on paperwork for another hiker. Behind them both, a large whiteboard displays a table titled ``Denali Backcountry Unit Availability''; it lists units and their capacities for the next five days. Most units show numbers like 4, 6 and 8; in a few, the word ``Full'' has been written in red.