Vesper Sparrow

Usually when I see a small bird standing on a fence post, it's a Savannah Sparrow. This bird seems to be lacking yellow "eyebrows" and has a white outer edge to it's tail feathers. The pattern on its cheeks does not look familiar to me, but maybe it's a female or a juvenile "something". I'm not good at Sparrow ID, but I checked my bird book and did a quick look on Google. Any help with ID would be greatly appreciated! It was seen yesterday (12 July 2014) , SE of Calgary, in the Frank Lake area.

My first stop was at Frank Lake, where I saw a few more Eared Grebes with their quite large "babies". The light was really bad, so it was impossible to get photos that showed colour and details. Will lighten one or two of them and see if that works. Saw Soras again - love these little guys, they are so cute. A few very distant White-faced Ibis, but I lucked out later, finding a lone Ibis at a slough somewhere around the lake. Also saw a couple of small birds that I'm not sure of the ID for, along the country backroads. Posted this one today and will upload a very poor photo of the other sometime soon.