trail to Farmington, some back roads to the causeway, then out to Garr Ranch at the southern end of the Antelope Island. It is all pretty flat and minimal traffic. The Legacy trail is nice because there is a parking lot right there in NSL, it's paved and very flat. If you do that as an out and back you'll probably be about 90 miles. Could easily find a way to tack on 10 more.