Yes, if you are an Oregon resident but only earned income in California, then you must file returns in both states if you were in California when you earned the income.
Were you physically present in California? You must have been physically present when you were earning the income in order for it to be taxable in California. If you earned all the income while you were sitting at your desk in Oregon, then you will not need to file a California tax return.
If you traveled to California and your work required you to stay overnight, then your travel expenses are deductible to the extent they were not reimbursed. The IRS allows you to deduct travel expenses, lodging, and half of the cost of meals and incidental expenses. If you didn't save receipts, you can use a per diem.
You can find more information about rules and where to enter the information in TurboTax in the link below.
