With regard to "Hotel covers" here's some interesting history of the New Harris Hotel shown on the first scanned cover from 1916. It was later sold and became the Julianna Hotel and was eventually razed and Juliana Park is now located on this former hotel site.
Based on these descriptions you can see how the hotel, once one of notable quality, later became something of less than acceptable standards:


When the hotel was last sold in 1968 it was described as follows:
Quote:
JULY 18, 1968 – ADA WEEKLY NEWS: Purchased by Durant Physician. One of Ada's oldest buildings, the Juliana Hotel complex was purchased just last week by Dr. Leroy Engles who bought the property from Alice S. Warren. The terms of the transaction were not announced. Formerly the Harris Hotel, the building was constructed in 1904, but has undergone many expansions and changes since that time. Dr. Engles said Saturday he will continue to operate the hotel, as is, for the time being. However, he added, "The building was purchased for investment purposes and we have plans for some changes within the next three to five years." Currently, the complex includes the hotel, a barber shop, western store, restaurant, shoe store, sho repair shop, insurance agency and loan shop. The hotel operated for about 40 years as the Harris Hotel. When it was opened in 1904, it was rated as one of the finest in Indian Territory. The hotel maintained an excellent dining room, spacious sample rooms in which "drummers" displayed samples of their firms wares, a billiard parlor and other comforts of the time. The owner, Sam Harris, originally a wholesaler at Shawnee, was one of the earlier investors in Ada property. He first built four one-story buildings on the site and then added a second story to provide 80 hotel rooms. The excellent accommodations of the hotel soon made Ada the weekend mecca for the traveling man and the hotel was the scene of many, early social functions. A vice president of the United States, Charles W. Fairbanks, made a speech in front of the hotel in October 1906. During its heyday in the 1920s and 1930s, the hotel counted among its guests governors, senators and various other officials, plus some of the most wealthy oilmen in the nation. It was bought by Julia Mae Smith about 1945 and the name was changed to Juliana. The property got a facelifting about 15 years ago.