It was extremely difficult to estimate the number of people at the Rainbow Gathering. We utilized a system of three traffic counters to calculate and confirm an estimated count. Two of the counters were historic in which we could determine prior year counts in the same area. This was determined to be approximately 75 vehicles each day for the same time period. The third counter was placed on a cattleguard just below the main parking areas. We used this counter to determine the number of vehicles. We then assumed that 2/3 of the count did not cross the counter more than once. For example 2/3 of the vehicles crossed the counter once going to the Gathering and once leaving the gathering We further assumed that each vehicle held three people.
(Traffic Count) X (2/3) X (3 People) = Total People
| . | Vehicle | People | |||
| . | Traffic | 2/3 Traffic | Daily | (Veh * 3) | Cumm |
| Date | Count | Count | Increase | + or - | Total |
| 6/26/97 | 0 | 0 | 0 | 0 | 0 |
| 6/27/97 | 700 | 470 | 470 | 1410 | 1410 |
| 6/28/97 | 1470 | 985 | 515 | 1545 | 2955 |
| 6/29/97 | 2440 | 1635 | 650 | 1950 | 4905 |
| 6/30/97 | 3597 | 2410 | 775 | 2325 | 7230 |
| 7/1/97 | 5368 | 3595 | 1185 | 3555 | 10785 |
| 7/2/97 | 6877 | 4610 | 1015 | 3045 | 13830 |
| 7/3/97 | 8405 | 5630 | 1020 | 3080 | 15890 |
| 7/4/97 | 10522 | 7050 | 1420 | 4260 | 21150 |
| 7/5/97 | 13109 | 8795 | -1735 | -5205 | 15945 |
| 7/6/97 | 15106 | 10120 | -1335 | -4005 | 11940 |
| 7/7/97 | 17015 | 11400 | -1280 | -3840 | 8100 |
| 7/8/97 | 18504 | 12400 | -1000 | -3000 | 5100 |
| 7/9/97 | 19202 | 12865 | -465 | -1395 | 3705 |
Historic records show that this traffic counter normally records approximately 75 cars per day. The 2/3 reduction takes this into account plus assumes that some traffic will return downhill.