| Year | Milestone | 
 | 2025 | NPS says PHNST Pimmit Run ford at Ft. Marcy to be repaired by end of 2025 | 
 | 2025 | PHNST feasibility study for Western Loudoun (Leesburg to WV) Released | 
 
  | 2025 | PHNST Comprehensive Management Plan put on hold by DOGE | 
  | 2024 | NPS secures funding for long-overdue PHNST Comprehensive Management Plan | 
 
  | 2023 | Prince William Co funds Powell's Creek Boardwalk design for $500,000 | 
 
 | 2023 | Annual Value to No. VA Economy of PHNST estimated at $494 million | 
 
 | 2022 | PHNST Superintendent Jeri DeYoung hired | 
 
| 2022 | Opening of Bull Run Loop Trail section under I66 (hiking/equestrian) along Bull Run | 
| 2022 | PHNST segment (1 mile) along Broad Run (accessed at Bles Park) opens (at NoVa Criminal Justice) | 
| 2021 | Loudoun County adopts ambitious trails plan | 
| 2019 | Kimley Horn report shows feasibility of PHNST segment Great Falls Park to McLean | 
| 2019 | Neabsco Boardwalk (Woodbridge) opens, key part of PHNST | 
| 2019 | Toole Design study shows feasibility for PHNST segment Lorton VRE to CCT at Pohick Creek | 
  
| 2017 | Evan Marshak becomes FTAS Webmaster | 
| 2017 | Fairfax Trails and Streams meets repeatedly with the I-66 Planning Team to advocate better routes for the Cross County Trail and West County Trail, away from traffic when possible. | 
| 2017 | Fairfax Co Board of Supervisors officially recognizes the Sully Loop Trail and the Bull Run Loop Trail | 
| 2017 | Fairfax City elevates the Snyder Trail, which FTAS advocated, to its highest transportation priority. Trail achieves $13.5 million in funding as part of I-66 widening. Construction bids to go out in late 2018. | 
| 2016 | FTAS advocates for the Sully Loop Trail and the Bull Run Loop Trails | 
  2015 | FTAS advocates the “Snyder Trail” to Fairfax City the original route of the Cross County Trail (allowing the CCT to follow the upper Accotink creek, avoiding 3 miles along busy roads) | 
| 2015 | Pickett Road Underpass opens in Fairfax City, part of a Cross County Trail reroute option FTAS has advocated. | 
  
| 2014 | Fairfax Co Board of Supervisors officially recognizes the West County Trail | 
2013 | Oct 26 and Nov 2: First West County Trail hike, led by Glenn Gillis of Sierra Club PRO | 
| 2012 | FTAS advocates for the Bull Run/Reston Trail (now known as the West County Trail). | 
| 2010-11 | Ed Pickens mentors six Eagle Scouts to build six bridges in northern Fairfax County, on the Potomac Heritage Trail north of Riverbend Park. | 
| 2007 | Cross County Trail Volunteer Committee wins Elly Doyle Award | 
| 2006 | May 6: CCT Opening Ceremony | 
2005 | June 15: Noman Cole Trail Opens (1 mile of Potomac Heritage Trail in Lorton), built by volunteers from FTAS and partner groups. | 
| 2005 | Dec 13: Volunteers from FTAS and partner groups, led by Fx Co Park Authority, assemble 27’ bridge on CCT south of Dulles Toll Road | 
  
| 2003 | “Ultimate Cross County Hike” literally crossed Fairfax County, from Occoquan (in Prince William Co.) to Algonkian Park (in Loudoun Co.) | 
| 2003 | CCT Volunteer Committee forms; Fx Co Park Authority with volunteers (Bev Dickerson, Randy Kerr, Bill Niedringhaus, Ed Pickens, Robin Rentsch, Sue Wakefield); meets quarterly for next 3 years til CCT is complete. | 
| 2001 | FTAS wins grants of $3000 from McLean Citizens Foundation and Fairfax History Commission to design and print large-scale historic map of Pimmit Run (these are for sale at ___). | 
| 2001 | FTAS wins Fairfax Co. Park Authority’s Elly Doyle Award | 
| 2000 | Supv. Gerry Connolly advocates for CCT; secures first funding ($400,000) | 
| 2000 | Fairfax Trails and Streams wins American Hiking Society Trail Development Award | 
| 1999 | First annual Pimmit Run Litter Cleanup | 
| 1999 | June 5-6: First Cross County Hike (Saratoga Elem School to Colvin Run | 
| 1999 | 3 Saturdays in November: Cross County Hike (Saratoga to Great Falls Vis. Center) | 
  
| 1998 | First partial Cross County Hike (Oak Marr northward) | 
| 1997 | First FTAS public trail-building worktrip, on Pimmit Run at Kent Gardens, with 8 volunteers, to repair a washout | 
| 1997 | First public advocacy of Cross County Trail, by Bill Niedringhaus | 
| 1992 | Friends of Pimmit Run formed, to advocate for the Pimmit Run Trail | 
  
| 1991 | First public advocacy of Pimmit Run Trail, by Bill Niedringhaus | 
| Ongoing | Ed Pickens and his FTAS crew maintain the Pimmit Run Trail, including 8 fords. | 
| Ongoing | Ed Pickens leads semiannual litter cleanups along Pimmit Run and other McLean streams |