Trees planted at Ehmen Park and Lake Helen Nebraska has a storied history regarding trees. After all, this was the birthplace of the first Arbor Day celebration on April 10, 1872, a proposed holiday from then Nebraska State Board of Agriculture vice president J. Sterling Morton. Recently, the city of Gothenburg had a tree-planting project at Ehmen Park, at the ...PLEASE LOG IN FOR PREMIUM CONTENT. Our website requires visitors to log in to view the best local news. Not yet a subscriber? Subscribe today!