I live in Oregon (I rent - do not own a home here). I work in the state of Alaska during the summer. The rest of the year I work in the state of Idaho. None of my wages are made in the state of Oregon

My w-2 shows all of my income reported to the state of Idaho. It shows tax with
Held for both Oregon and Idaho (no income reported to Oregon). Alaska does not have a state personal tax.

Am I subject to all of my wages for Alaska and Idaho on my Oregon return as being taxable?

Yes, because the state where you live has the right to tax ALL world-wide income.

You can claim a credit for the taxes paid to Idaho on the Oregon state tax return. Any competent tax preparer will know how to do this.