Temporarily suspended until further notice. The Durham Museum’s River City History Tours on Ollie the Trolley explore Omaha’s rich heritage. Along the way, participants will learn amusing and not-so-well known facts about significant people and places in our beautiful city’s history. Private River City History Tours Available year-round for groups of up to 42. Grab your friends, co-workers or family members and hit the streets for a private River City History tour. Pick your date and time (subject to availability) and the tour of your choice and have the whole trolley to yourself!