It appears Western States transgender policy is one we would support at LetsRun.com. Someone's gender is accepted at face value but anyone finishing top 10 or scoring in an age group needs to show they received hormonal treatment for at least a year.
Here is their policy.
A runner’s self-declared gender at registration will be accepted at face value. The sole reason for this policy is to ensure fairness regarding competition for awards and records. Therefore, there shall be no basis for, or tolerance of, any challenge to a runner’s self-declared gender unless a top 10 finish or age group award is at stake.
WSER shall have the sole authority to review any challenge regarding the gender status of a top 10 finisher or age group winner. Any such challenge must be made directly in person or writing to the Race Director with the utmost discretion and respect for the privacy of all parties involved. WSER in its sole discretion will determine whether there is a legitimate basis for the challenge.
Gender Status Review
In the event of a challenge, WSER may ask the runner for documentation from a medical doctor or healthcare provider or other qualified professional certifying that the entrant has undergone continuous, medically supervised hormone treatment for gender transition for at least one year prior to the race. (See WSER Medical Clearance.) Transgender entrants, at their option, may provide the medical documentation related to their gender transition to the Race Director prior to the race. All information about the runner’s gender identity and medical information, including any information provided pursuant to this policy, shall be kept strictly confidential.
The final decision regarding the entrant’s gender status shall be within the sole discretion of WSER. If it is determined that the runner is not in compliance with WSER’s rules for transgender entrants, the runner will be allowed to keep their WSER finisher’s buckle but any top 10 finisher or age group awards shall be returned to WSER. WSER will attempt to protect the runner’s privacy interests to the maximum extent possible.