Nobody owns the challenge, so the first job is to decide your own rules. If you'd like a club to certify your finish at the end, read that club's rules first — each one defines for itself which distances and events count.

• Pick a minimum distance and keep it for all 50 states. Changing the standard halfway is the most common reason people re-run states.
• Count official finishes. A published result is dated, public and easy to prove years later.
• Decide about Washington, DC. It isn't a state, but many runners add it as stop 51. RaceRove lists races in Washington, DC on their own page.
• Decide whether past races count. Most runners include races they finished before they started the challenge.

Fifty separate trips is the slow, expensive way to do it. The runners who finish tend to plan in clusters and seasons:

• Group neighbouring states into one trip. Every state page links to the states that border it. The Northeast and Mid-Atlantic are the easiest places to collect several states in a few days.
• Follow the weather. Save northern and mountain states for the warmer months and use winter for the South and Southwest, when their calendars are busiest.
• Schedule the scarce states early. States with short race calendars leave you fewer weekends to choose from, so build those trips around specific races.
• Treat Alaska and Hawaii as holidays with a race attached, and book them well ahead.
• Keep records as you go. Log the date, distance and result for every state while you still remember the day.

For the full method — rules, regional clusters, seasons, budgeting and the mistakes to avoid — read How to Run a Race in All 50 States. If half marathons are your distance, how to choose a half marathon covers picking races for a 50-state project.