Southern Mono Historical Society Inc

Nonprofit profile at a glance

EIN: 770053500
IRS 990-EZ coverage: 2016–2025
Forms available: Form 990-EZ 2025, Form 990-N 2015
Location: Mammoth Lakes, CA, USA
Phone: 7609346918
Rating: 78
Verdict: SUPPORTED
Rating confidence: Moderate

Reported finances

Revenue: $11,421
Expenses: $70,956
Assets: $39,703
Liabilities: $21,800

Source: IRS Form 990-EZ. Selected filing: tax year 2025. Amounts in USD.

Leadership & pay

4 people listed

Executive titles in this filing

Robert Joki (President & CEO)

People named in this filing

Kevin Green (Director)
Robert Joki (President & CEO)
Tony Rojas (Director)

Selected names, not a complete roster or a statement of current roles. Open leadership details for the complete filed list.

Source: IRS Form 990-EZ. Selected filing: tax year 2025. Names and roles reflect this filing, not necessarily current officeholders.

Overview

Mission

Historical preservation and education

Operating model

Revenue model: Other-operating. 100% of the money available for current operations came from other operating revenue.
Distribution model: Direct operator. The filing allocates 100% of reported program-service expenses outside its grant, affiliate-payment, and member-benefit lines. This expense classification does not rule out separately announced grant awards.

The verdict

SUPPORTED - A large share of available resources goes toward mission work and the filed numbers largely add up. Expenses are high relative to revenue and program spending has declined or grown slowly.

Rating breakdown

Financial Efficiency: 88
Transparency & Controls: 82
Sustainability: 19
Growth: 0

Detailed rating inputs

Financial Efficiency

Mission deployment rate: 100%; rating input score 100
Program expense ratio: 67.7%; rating input score 68

Transparency & Controls

Consistency checks: 100%; rating input score 100; 51st percentile among comparable filings
Major donor itemization: Limited

Sustainability

Operating margin: -521.3%; rating input score 3; 3rd percentile among comparable filings
Total-asset coverage ratio: 0.56; rating input score 34; 34th percentile among comparable filings
Liabilities to assets ratio: 0.55; rating input score 7; 7th percentile among comparable filings
Officer compensation ratio: 0%; rating input score 56; 56th percentile among comparable filings

Growth

Program expense growth: -0.4% per year; rating input score 0; 46th percentile among comparable filings
Revenue growth: -2% per year; rating input score 0; 42nd percentile among comparable filings
Asset growth: -4.8% per year; rating input score 0; 25th percentile among comparable filings

Details

Where the money goes: 100% of revenue deployed · 67.7% of spending went to programs
Governance: Filed governance answers
Accomplishments: 1 filed program accomplishment · $48K in reported program spending
Leadership: top reported pay $0 · 4 people listed
Consistency: 8 of 8 current checks pass
Schedules: 2 filed schedules
Filing history: 10 filing years from 2016 to 2025
Contacts: How to reach this organization
Grant readiness: Federal tax and exclusion status, award history, and grant-maker relationships.
People: Everyone the filings name, and which of them the filings identify by more than a name.

Key Signals

Signals prioritize questions for review. They are not findings of misconduct.

Grant-readiness screening is separate from the live rating, not a measure of program quality. Review the source records before making a grant decision.

High — Sustainability: Operating margin scored 3/100.
High — Growth: Program expense growth scored 0/100.
High — Growth: Revenue growth scored 0/100.
High — Growth: Asset growth scored 0/100.
Moderate — Sustainability: Total-asset coverage ratio scored 34/100.
High — Sustainability: Liabilities to assets ratio scored 7/100.
Review — Sustainability: Officer compensation ratio scored 56/100.
High — Grant Readiness: California registration: this organization is not authorized to operate as a charity in California.