Sr. Administrative Assistant / Office Manager, Office of the CEO

About Alta

Alta Resource Technologies (Alta) is a next generation mining company that uses synthetic biology to separate critical minerals from conventional and unconventional resources, including e-waste. Founded in 2023, the company is expanding its team in Boulder, CO. The exponential growth of new tech industries, as well as the information technology sector, are driving historic growth in mineral demand and stressing existing supply streams. Meeting new demand, diversifying the supply chain, and producing minerals in a more sustainable manner requires the rapid development, deployment and scaling of new technologies. This mineral challenge represents a historic opportunity for technology development and value creation. Alta is proud to be at the vanguard of this mega trend.

Location: Boulder, CO — onsite, with occasional travel to other company facilities

Reports To: Chief of Staff

Supports: Chief Executive Officer, with support to VPs and C-suite as needed

Status: Full-time, Non-Exempt

About Us

Alta is reinventing how the world sources critical minerals — using protein-based chemistry to extract rare earth elements and other essential materials from challenging feedstocks with unmatched selectivity. By dramatically reducing the cost and environmental impact of mineral separation, Alta is making it possible to unlock new sources of supply for 21st-century technologies. As global demand accelerates, securing these materials has become one of the most urgent challenges facing U.S. competitiveness and national security. Backed by top investors and government partners, Alta is growing fast and hiring mission-driven scientists and engineers to help us scale our platform and transform the future of mining.

Role Summary

Alta is hiring a Sr. Administrative Assistant / Office Manager to support the Office of the CEO. This role is the operational backbone of Alta’s executive team — owning the scheduling, travel, workplace, and coordination work that keeps a fast-moving leadership group running, and doing it well enough that leadership stops thinking about it.

The position exists because Alta is scaling. At 39 employees today and growing past 50 across multiple facilities, the volume of executive administration and workplace operations has outgrown what can be absorbed alongside strategic work. This role takes ownership of that volume so that the Office of the CEO can focus on planning, execution, and organizational infrastructure.

This is a high-trust, high-visibility position. The person in this role sees calendars, board logistics, personnel information, and financial documents before almost anyone else does. Discretion is not a preferred quality here; it is the job.

Key Responsibilities

Executive Scheduling & Calendar Management

Own calendar management for the CEO, and for VPs and C-suite leaders as needed

Schedule and reschedule against shifting priorities, resolving conflicts without escalating each one

Protect focus time and enforce meeting standards set by the Chief of Staff

Coordinate complex multi-party meetings across functions, facilities, and external stakeholders ● Manage the logistics of recurring leadership meetings, including room, materials distribution, and remote access

Travel, Expense & Vendor Administration

Book and manage domestic and international travel for the executive team, including itineraries and contingency planning

Administer vendor relationships for office services: onboarding, invoicing, renewals, and issue resolution

Maintain purchasing and supply processes across facilities within approved budgets ● Prepare and submit expense reports; track receipts, reconcile against policy, and follow through to reimbursement

Meeting & Communication Support

Assemble, format, and distribute meeting materials and agendas prepared by the Chief of Staff ● Capture notes and action items in leadership and cross-functional meetings, and route them into the company’s tracking system

Follow up on outstanding action items and flag items at risk of slipping

Draft and distribute internal communications and announcements as directed ● Serve as a professional first point of contact for external visitors, partners, and investors

Workplace & Office Operations

Own day-to-day office operations at the Boulder site: supplies, equipment, facilities requests, and workspace readiness

Coordinate with building management, service providers, and IS on workplace issues ● Support the people-facing side of new site readiness alongside the SVP of Operations, including workspace setup and supply logistics

Maintain office procedures and documentation so processes are repeatable rather than person dependent

Partner closely with the Facilities Ops Manager to stay current on building operations and maintenance activity (This role is not responsible for facilities upkeep directly, but is expected to be in the know)

People & Onboarding Coordination

Schedule interviews and coordinate candidate logistics with hiring managers and the external HR partner

Execute new-hire onboarding logistics: workspace, equipment, access requests, first-week scheduling, and welcome materials

Maintain HR and compliance documentation and personnel records, handling confidential information with strict discretion

Support employee programs and recognition activities

Events & Employee Experience

Plan and execute company events, team gatherings, and all-hands meetings across sites

Coordinate logistics for board meetings and investor visits, including catering, materials, and on site arrangements

Contribute to a consistent employee experience across all Alta locations

What Success Looks Like

This role is evaluated on reliability and on the capacity it creates for others. Within the first year:

Executive scheduling runs without escalation; conflicts are resolved at this level rather than passed upward

Travel and expense administration is fully owned, with reimbursements and reconciliations current

Office and workplace operations run on documented, repeatable processes rather than institutional memory

Onboarding logistics are complete before every new hire’s first day

Board and investor visit logistics execute without leadership involvement in the details

Executive administrative and workplace volume no longer sits with the Chief of Staff

Growth Path

This position is the first dedicated hire in the Office of the CEO and sits at Level 3 on the G&A Admin track. As Alta scales past 50 employees and across multiple facilities, the scope of this role is expected to grow toward executive support for additional leaders and project coordination work, with a defined path along the Admin track toward Executive Assistant (Level 5) and Sr. Executive Assistant (Level 6). Strong performers may also move laterally into the Strategy & Execution track.

Required Qualifications

Associate’s or Bachelor’s degree, or equivalent experience

Three to five years of administrative, executive support, or office operations experience, ideally in a startup or high-growth environment

Demonstrated ability to manage complex calendars and competing priorities for senior stakeholders

Proven discretion with confidential personnel, financial, and board information

Strong written and verbal communication, including with external partners and investors

Highly organized, with a bias toward closing loops and following through without reminders

Drives tasks and projects to full completion, following up repeatedly and closing gaps in information, timing, or direction without being asked twice

Comfortable working independently and confidently making judgment calls in ambiguous situations

Proficiency with Google Workspace or Microsoft 365, video conferencing, and expense management tools

Availability outside standard hours as needed, including evenings or weekends for special eve