the COVID-19 crisis effort in early March 2020. Initial work of the CEOC included the main operations of: disease surveillance; procurement of personal protective equipment (PPE) and mechanical ventilators for the state response; purveying evidence-based messaging for the public on websites and social media; and planning for surge capacity (US DHHS, 2007) , while also serving as experts and advisors to the Governor's Office.
Initial surge capacity planning in Colorado was largely a partnership of the CEOC and the Colorado Hospital Association with an emphasis on tracking the numbers of available hospital beds, critical care beds (and ventilators), and organizing facility and staffing resources across the acute care health system network, particularly on the Front Range of Colorado that includes a majority of the state's population base along the I-25 corridor. Hospital-based surge planning fell largely into the Tier 1 and Tier 2 categories ( Figure 1 ) of facility types, Tier 1 comprising of the most critically ill COVID-19 patients requiring mechanical ventilation, and Tier 2 patients acutely ill and requiring hospital-based medical and nursing care. At this time, pre-"Stay at Home" order, state epidemiologists anticipated needing over 5,000 Tier 1 beds to meet surge capacity needs (Polis, 2020a) .
On the third week of March, the CEOC expanded its organizational chart and planning efforts to begin preparation for ACSs (US DHHS, 2020) across the state. ACSs are defined as subacute facilities that typically are community-based in arenas, stadiums, convention centers, dormitories, and even converted hotels (US Army Corps of Engineers, 2020). It was estimated at the time that if the population illness curve was not flattened (Figure 2 ), a range of 15,000-30,000 beds would be needed for COVID+ Coloradans (Polis, 2020b) .
When planning for the ACSs became a priority on the third week of March, CDPHE public health planners were redeployed to the CEOC to lead the effort. A public health nurse educator (Harpin) was invited to consult on the planning efforts to bring training expertise, to bring "an eye" to interprofessional education, disaster care expertise (I was deployed to Louisiana in 2015 for Hurricane Katrina relief work), and a focus on nursing education as a primary workforce under consideration for ACSs. A series of topics (Table 1) These first trainings were brief 10-15 min recorded lectures and handouts that ACS workers would review prior to arrival on-site, to prepare them quickly in addition to the deeper training they would receive in-person with skills check-off. Trainings were developed so that they could easily also be integrated into undergraduate nursing education coursework in case universal COVID nursing education would be of use as standard curricula. Initial topics identified as critical included: COVID 101; introduction to Incident Command Structure; nursing care of the COVID-19 Patient; PPE for COVID care standards; provider self-care; body mechanics; caring for adults with low-mobility; and access and functional needs framework of patient care. We planned for all content to be publically accessible, at least initially, without password protection.
Over the course of the first week of April 2020, trainings were developed with the assistance and expertise of four undergraduate senior nursing students (whose clinical placements were canceled due to the crisis; work on these modules were counted as community health clinical time), recorded, and stored on the CU Nursing university server "cloud", then curated on a new webpage dedicated F I G U R E 1 Medical surge concept of operations, tier 1 through tier 4 settings F I G U R E 2 COVID-19 population incidence curve model, "Flattening the Curve" | 3 HARPIN to COVID-19 on the CU Nursing website (https://nursi ng.cuans chutz.edu/coron aviru s/covid -nursi ng-care). As these trainings were developed for the state response, there was debate on where these should be housed. It was quickly determined that keeping them branded and accessible to changes by university webmasters would be far more nimble than hosting on the State of Colorado website.
Still, a link to the trainings was created on the State's COVID-19 homepage.
While a number of ACS sites were being planned across Colorado, the primary location developed with the most attention was at the Colorado Convention Center with a capacity for 2,000 Tier 3 beds.
Engineers partnered with CEOC leaders to build the site over the course of 9 days, framing patient spaces with 8-foot drywall to give each patient a 10 × 10 foot room, each supplied with an oxygen regulator akin to other ACSs already deployed in other U.S.
cities. Concurrent with the build-out (details of which are beyond the scope and aim of this paper) and statewide stay-at-home order, state epidemiologists relayed the good news that incident COVID-19 cases were decreasing and the population curve muted, thus tempering the crisis nature of opening the ACSs. These new case projections gave our training team more time to thoughtfully plan for more detailed in-person trainings, and to shift efforts on creating standard operating procedures for ACSs that would reflect more acute care hospital functioning rather than disaster care.
In mid-April, Denver Health and Hospital Authority (DHHA) was 
The first half-day training for non-patient facing CCC staff was held on June 1, 2020 and included the topics noted in 
In addition to the core training team, 21 trainers were ordained as master trainers for the ACSs. In the pilot training, 25 participants attended the non-patient facing training and 47 in the patient-facing sessions. At this writing in mid-June 2020, no formal program evaluation has been distributed to either master trainers or participants, though the core training team has plans to create and distribute a survey evaluation for all participants after the next round of trainings, especially to elicit process evaluation data to improve training.
Anecdotal evidence from master trainers and clinical staff who have worked in COVID+ settings was very positive in terms of content, training format, and length of training. One RN said simply "I wish I had had this training when I showed up to work the COVID unit in California." 
History will inform COVID-19 response in the short-term as importantly as it will long in the future, akin to how lessons were uncovered from the Spanish Flu pandemic in writings such as John Berry's classic The Great Influenza (Berry, 2004) . That historical narrative has been as important for workforce education as has recommended emergency preparedness training for undergraduate nursing students (American Association of Colleges of Nursing, 2008) and public health nursing practice (Association of Public Health Nurses, 2014).
Indeed, these public access trainings have been shared within and outside our university for others to consider embedding in curricula.
The purpose of this paper was to share an experience in Colorado to help others who might be concurrently developing or adapting ACS training as we prepare for a likely second wave of COVID-19 cases in the United States. Ultimately, a fantastic outcome would be that training and ACS facilities would not be needed, making these written words merely history. In the words of Colorado Governor Jared
Polis at an April 10 (2020) Press Conference: "I really hope we don't have to use this facility at all. But we prepare for the best, hope for the best, and not be caught flat-footed."