As others have said, without seeing the image it's hard to answer this, but I'll throw this out anyhow:
When I shoot landscapes I shoot as far to the right as I can without blowing the highlights. This usually results in an image that looks very over exposed. In Lightroom I bring down the exposure, but this alone normally results in an image that still looks washed out and lacking contrast. What usually corrects this is using the black and white sliders to bring their values to be just touching the edges of the histogram, and the shadows slider to fine tune the midtones. Sometimes I'll have to adjust contrast a little, and maybe highlights (usually reducing them.)
This is basically what I find works for my stuff, don't know if it will apply to yours.