United Airlines continues to redraw its route map during the pandemic, with the latest causality being three small U.S. cities.The Chicago-based carrier filed plans over the weekend to pull out of three airports later this year and into early 2022, as first seen in Cirium schedules and later confirmed by the airline.United will no longer serve the following airports effective on the dates listed below:Pierre, South Dakota (PIR), ends on Jan. 3, 2022.Twin Falls, Idaho (TWF), ends on Nov. 30, 2021.Watertown, South Dakota (ATY), ends on Jan. 3, 2022.Want more airline-specific news? Sign up for TPG’s free new biweekly Aviation newsletter!Interestingly, the two airports in South Dakota qualify as Essential Air Service (EAS) markets, meaning that the federal government provides subsidies to a chosen airline to guarantee service to these cities.Those subsidies (totaling nearly $7 million) were previously awarded to United Express partner Skywest Airlines, though that contract expired in April 2021. Before the expiration, the Department of Transportation solicited proposals from carriers interested in providing service to these markets, and Englewood, Colorado-based Denver Air Connection won the contract (valued at nearly $5 million) through May 31, 2023.While United could’ve pulled out of Pierre and Watertown at the expiration of its EAS contract, it decided to continue to serve both markets without the government subsidy. In October, United Express partner Skywest Airlines lost a re-bid on the EAS contracts for the cities, as the DOT reaffirmed its decision to go forward with Denver Air Connection flights.(Photo by Zach Griff/The Points Guy)Losing the re-bid is the nail in the coffin for United Express service to these South Dakota cities, as explained in the following statement from Skywest:SkyWest flights, operating as United Express in Watertown and Pierre, South Dakota, will end in early January following the Department of Transportation’s (DOT’s) recent decision to not re-bid under the Essential Air Service (EAS) program.Denver Air Connection will become the sole carrier in Pierre and Watertown, while Delta Connection partner SkyWest Airlines will continue to serve Twin Falls with nonstop flights from Salt Lake City (SLC).Sign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.The move to pull out of these cities comes as the pandemic continues to have an outsized effect on small cities without enough demand to warrant jet service.For example, late last year, American Airlines suspended service to several smaller cities. Flights resumed at some of those airports, only to be cut again in places like Williamsport, Pennsylvania (IPT) — which lost airline service altogether as of Oct. 1. Recently, Delta filed plans to pull out of Durango, Colorado (DRO), while United made headlines for ending service to Rochester, Minnesota (RST).In addition to United terminating service at the three airports mentioned above, the airline is also cutting a route to another small city — Joplin, Missouri (JLN) — from its hub in Houston hub, effective later this month.In a statement to TPG, SkyWest cited demand patterns as the reason for the cut.SkyWest will discontinue United Express flights from Twin Falls, Idaho to Denver and Joplin, Missouri service to Houston later this month. SkyWest-operated United Express service from Joplin to Chicago O’Hare and Denver will continue. We are continually working with our partners to evaluate demand and service levels across our network; customers who are booked beyond these service dates will be contacted for rebooking options.United Express serves Joplin from Chicago and Denver, both of which are subsidized by the federal government under the EAS program. Houston wasn’t covered under the terms of the contract, and now it’s getting axed due to the low demand.