Professional Registration of Peak Engineers:
| ARIZONA | ARKANSAS | CALIFORNIA | COLORADO |
| FLORIDA | GEORGIA | IDAHO | ILLINOIS |
| INDIANA | IOWA | KANSAS | KENTUCKY |
| MARYLAND | MASSACHUSETTS | MICHIGAN | MINNESOTA |
| MISSOURI | MONTANA | NEBRASKA | NEVADA |
| NEW JERSEY | NORTH CAROLINA | NORTH DAKOTA | OREGON |
| PENNSYLVANIA | PUERTO RICO | SOUTH CAROLINA | SOUTH DAKOTA |
| TENNESSEE | TEXAS | UTAH | VIRGINIA |
| WASHINGTON | WISCONSIN | WYOMING |