I was in Costco today and saw chopped romaine lettuce with the KORC symbol. I was wondering if anyone knows if this symbol is accepted by the OU or other large Kashrus organizations.

I was in Costco today and saw chopped romaine lettuce with the KORC symbol. I was wondering if anyone knows if this symbol is accepted by the OU or other large Kashrus organizations.

The Atlanta Kashrus Agency does not recommend the KORC.
The AKC does not recommend the KORC certification. Lettuce products with this certification have been found to have have insects and require additional washing and checking.
Considering the opacity around the acceptability of different kashruth certification organizations in America, I don't think many people will be able to accurately answer this question. That being said, KORC appears on neither the cRc nor KosherQuest (Rabbi Eidlitz, based in California) lists of reliable hashgachot (although they of course have disclaimers that absence from the list does not mean it is not acceptable).
This info is on Kashrut.com :
Orthodox Rabbinical Council of San Francisco 1851 Noriega Street, P.O. Box 22491, San Francisco, CA 94122 415-564-5665, Fax: 415-665-0394 Rabbi Jacob Traub, Chairman Email: orcsf@aol.com
I could not find any info on any kashrut site regarding its reliability. As a matter of fact, various web forums debate its kashrut, with none mentioning why.
I think, therefore, on this, you may have to relay this to your rav. I know some rabbanim are lenient regarding a questionable hechsher on produce. (My rav, e.g., allowed all cut up fresh fruit from Costco even without a hechsher on it.)
I have posed this same question to Haredi and Modern Orthodox in our community.the simple answer is buyer beware. Neither crc nor cor (Canada) list them, and the reference card(COR) that I hand out to converts in Calgary does not list them. I would avoid them, unless a major hescher approves them. It is after all, about publishing clear rules, available to the public and rabbinic users alike! That is to say... how do you certify breads,broccoli, cauliflower, nuts and bulk foods? What is the laws of dairy and fish and MEAT? My great uncle started one of the first meat plants under Lubbavitch supervision. I only accept what I can verify. Yes, sometimes you may make a mistake, just don't do it again...Hashem understands and forgives.