The move was spurred by several cases of genetic contamination in the region that rendered non-engineered crops unsellable on the export market.
If the mapping goes ahead, Oregon would be the first state to mandate measures for coexistence between modified and non-modified crops.
Biotech companies and farmers who plant GMO crops say they already coexist and that mapping could lead to crop sabotage.
Organic farmers and others say a mandatory mapping system could increase transparency and help pinpoint the cause and location of genetic mixing.
Oregon regulators say they currently don't have the authority to map GMO crops, but the legislature could grant them the option.
A U.S. Department of Agriculture committee has recommended informal neighbor farmer agreements and an insurance system to pay for damages resulting from GMO contamination. But organic farmers are pushing for more disclosure, formal prevention measures and a system to hold GE growers liable for cross-pollination.
In Oregon, where over 200 crops are cultivated on nearly 24,000 farms, most crops do not have genetically modified counterparts, as only a handful of GE crops such as corn, alfalfa and sugar beets are permitted in the U.S.