When shooting toward strong light sources, it is **imperative** that the front element of the lens be immaculately clean. It is even more critical that the rear element of the lens be absolutely,positively, immaculately clean and free of grease, dust, and any form of slight smearing. If you have a UV, skylight, or other filter on the front of the lens, remove it. When the strong light source is imaged against a predominantly dark field, like foliage, tree lines, or any backdrop that constitutes what is called a "dark field", the tendency of the lens to show a maximum amount of either flare, ghost, or veiling glare, is exceptionally strong. So....make sure the lens is immaculately clean. Use a lens hood. Have a piece of dark cardboard or baseball cap or hat, on hand to shield the lens front from direct sun if you want to minimize ghosting (images of the lens diaphragm on the picture area), or flare (colored blobs of light,simply description) or veiling glare (an overall, foggy look that lightens the blacks and lowers image contrast). If possible, have an assistant hold the light blocking device so that is literally casts a shadow on the front of the lens!
If you use a flash, you need to add something like a 1/4 or 1/2 CTO ( a fairly mild color temperature adjusting filter, orange) over the flash. The natural light at that time of day is quite "warm", but the light from an electronic flash is 3,000 to 4,500 degrees Kelvin cooler (ie "whiter" you might say). Just blasting a flash at a backlighted subject shortly before sunset looks, well, not natural. The absolute, positively BEST places to shoot into backlight are where LARGE, lighter colored buildings reflect the rising or setting sun and create natural, lovely fill lighting. White, tan, beige, etc buildings create a HUGE source of reflector fill when the sunlight hits their facades. You live in Utah--surely you can scout around and find a nice location or two where the setting sun hits a large building. THis will allow you to shoot exposures at either "over" "right on" or slightly "under" exposure settings. ANd get beautiful results.
Second thing: make sure the camera's contrast level or Tone Curve setting is set to LOW; you do NOT want to shoot jazzed-up images in backlighted conditions; It's better to have a slightly lower-contrast image capture, and then to jazz it up in post, rather than have the highlights burn out because the camera was set to High Tone Curve (ie, high contrast). Same thing goes for the various "scene modes", like Vivid or Direct Print, etc...you do not want to use such settings, or you risk having images that are too high in contrast. It's much,much better to shoot, then post-process the images carefully, to get the shadowed side looking the way you want it to look.
Normally, the natural light is quite "warm", so set the camera white balance to 6,800 degrees or to Shade when photographing that close to sundown. AUTO WB will possibly be all over the place. Last thing: you can shoot this with a blown-out background, exposing for the shadowed side of the face, and allowing ther background to "blow out" and to be overexposed quite severly; the key in doing that is to make sure the background is fairly clean and uncluttered, and that the subject matter actually is conducive to such a look: females, children, horses, cattle, romantic scenes all lend themselves to blown-out, backlighted exposures and post-processing. When shooting in-camera JPEGs, it is critical that the white balance be set correctly--6,800 degrees or so when close to sunset, AND that the image saturation and tone curve settings not be excessively "jazzy". When shooting JPEGs, the exposures can be adjusted for the look you want, and this is a fantastic type of situation in which to use the AUTO-bracket feature, and to shoot a baseline exposure, and two others. If you want the bright look, make the two others "overs".