Peoria stacks itself on the bluff above the river, and the drive along the top looks out over water wide enough to pass for a lake, with the hillside timber falling away below in oak, hickory and walnut. Durdel & Sons Tree Service works those slopes and the flat neighborhoods behind them, where a century of shade trees leans over brick streets and porch roofs. The days run to tree trimming and pruning that takes weight off a long limb, tree removal when a hillside tree has begun to tip toward the house, and storm damage cleanup after the wind funnels up the valley and finds every weak crotch in town. A crew has done right by a place when the drive is clear by dark, the ruts are smoothed out, and the tree left standing looks lighter than it did at noon. On the bluff in late October, that lightness is the difference between a view and a worry.