Maynard joined in the logging activity at New York-Alki (later Seattle), near the mouth of the
Duwamish River on Puget Sound. Instead of selling his wood to shippers at $4 a cord, he leased a vessel from Captain Felker, using the wood itself as security, and sold the load in San Francisco at ten times the price. With that money, he bought the fixings for a general store and briefly set up in competition to the only other such store on Puget Sound, which was in
Olympia and owned by Catherine's brother. Mike soon agreed to his sister marrying Maynard, apparently on condition that they move the store to Duwamps and do something about that prior marriage. In April 1852, Maynard claimed, as a married man, a tract of land of 640 acres in what is now Seattle's
Pioneer Square neighborhood, and hired Indians to help him build a combination cabin and store. According to historian
Bill Speidel, the land he preferred was the undeveloped southern part of
Carson Boren's claim, but while Boren was out of town,
Arthur Denny shifted Carson's claim north to make room for Maynard. Maynard's building became a hub of activity when Maynard became King County's first Justice of the Peace. in return, the legislature passed an unusual bill granting Maynard a divorce.{{cite web Maynard developed many clever ways to improve his property and his city. For example, he obtained the right to host the post office at his store; as a result, everyone had to come to his establishment to get their mail. He sold a lot cheaply to blacksmith Lewis Wyckoff; people needing smithing therefore came to Seattle instead of its rival
Port Madison. Perhaps his greatest coup was persuading
Henry Yesler to set up a steam sawmill on land sliced from the north part of Maynard's claim and the south part of Boren's. This sawmill helped establish Seattle's economic ascendancy. When the only lawyer in Seattle died in a canoeing accident, Maynard studied law and was admitted to the bar in 1856. In 1857, Doc Maynard traded his "downtown" acreage for Charles C. Terry's farm in West Seattle, but this new enterprise did not prosper; he and Catherine then opened a two-room hospital in what is now Pioneer Square. This enterprise failed because a number of settlers refused to use the hospital after the Maynards insisted on serving both whites and Indians. ==Later life==