Can I claim exemption on capital gains in Oregon?

Can I claim an exemption for tax on gains of rental home sale in Oregon because I will be taxed on these gains in Montana where I am a resident?  Form OR-18 and Form WC (Oregon) are the forms I'm working on.   Or is there a partial exemption I can take given that MT and OR have different rates of taxation on capital gains.  My goal is to receive maximum proceeds from the sale rather than pay expected taxes at too high a rate if I can claim some exemption from Oregon capital gains tax rate.  Moreover, MT won't take taxes until they are due.