Sparrow ID? Jackson County

[bruc...@yahoo.com]

I have photographed a sparrow at Arapahoe NWR, North Park that has me stumped. http://brucecyg.smugmug.com/Photos/For-ID

I believe it is a juvenile Stagebrush Sparrow or Vesper, or maybe something else entirely. It has a hint of malar stripes that point to a sparrow and white outer edges to the tail. Both Stagebrush and Vesper have that according to Sibley. Although the bill looks a bit big for those sparrows. Any ideas on what this bird could be would be appreciated.

Bruce Cyganowski
Bruc...@Yahoo.com
Brucecyg.Smugmug.com
Kittredge, CO